How to Make Cottage Pie
To make cottage pie, start by sauteing the onion, carrots, celery, and garlic, add the beef, and brown it for 5-7 minutes. Next, stir in the flour, tomato paste, broth, red wine, thyme, bouillon cube, and bay leaves and simmer the mixture for 30 minutes. Then, carefully ladle the pie filling into a glass, oven-safe baking dish. Boil and mash the potatoes, spoon them over the beef mixture evenly, and drizzle with butter. Finally, bake the pie for 25-30 minutes at 350 °F until the top is golden.
Chop up the onion, carrot, and celery. Use a clean cutting board and sharp kitchen knife. Rinse off the carrot and celery stalk, and then cut them into ⁄ 2 inch (1.3 cm) pieces. Cut up 1 white onion, discarding the skin. Set the vegetables to the side. You don't need to peel the carrot beforehand, though it won't hurt anything if you do. Heat 1.5 tablespoons (22 mL) of olive oil on medium-high heat. Put a skillet on the stovetop, and turn the burner on to medium-high. Add the oil to the pan, and heat it for 30 to 45 seconds, or until it starts to sizzle. If you don't like olive oil, you could also use coconut oil, avocado oil, grape seed oil, or any other alternatives you prefer. Satué the onion, carrots, celery, and garlic for about 3 minutes. Take the vegetables from earlier and add them to the hot pan. Also add in 2 minced garlic cloves. Stir and sauté everything for about 3 minutes, or until the vegetables start to turn soft. If the vegetables start to burn, turn the heat down to medium. Add the beef to the pan and brown it for 5 to 7 minutes. Put the 1.5 pounds (680 g) of ground beef into the pan with the oil and sautéed vegetables. Continually stir and break up the beef so it cooks evenly. If you were making the classic shepherd's pie recipe, you would simply use lamb in place of the beef. Always use fresh or defrosted beef. Mix in 1/4 cup (40 grams) of flour to the beef and vegetables. After the majority of the beef has been browned, add the flour to the skillet. Stir everything together thoroughly to remove as many clumps of flour as you can. The flour helps thicken the beef and vegetables, giving it a gravy-like consistency. Combine the rest of the ingredients with the beef. Measure out 1/4 cup (55 grams) of tomato paste, 2 cups (470 mL) of beef broth, ⁄ 2 cup (120 mL) of red wine, and 1 teaspoon (1 gram) of dried thyme into the hot skillet. Also add in 1 beef bouillon cube and 2 dried bay leaves. Stir everything together until the bouillon cube has dissolved. If you don't want to add wine to the recipe, use the same amount of water instead. Simmer the mixture for 30 minutes, or until it starts to thicken. Leave the heat on medium-high and set a timer for 30 minutes. Check and stir the skillet every 5 minutes to prevent the bottom from burning. If after 30 minutes the mixture is still not a gravy-like consistency, cook it for an additional 5 to 10 minutes. If you're having problems with your mixture thickening, try mixing 1 tablespoon (15 mL) of cold water with 1 tablespoon (9 grams) of cornstarch in a small bowl. Then add that to the skillet and mix it until the liquid thickens. Put the mix into an 11 by 7 inches (28 by 18 cm) baking dish. Turn off the burner and carefully ladle the entirety of the cottage pie interior into a glass, oven-safe baking dish. Preferably, use an 11 by 7 inches (28 by 18 cm) dish, though you could also use a circular 9 by 9 inches (23 by 23 cm) pie dish.  Use caution when transferring the contents of the skillet! Use oven mitts if you need to hold the side of the pan or if the baking dish gets too hot while you're filling it. When everything goes into the oven later, all the ingredients will already be cooked. The main concern is making sure everything is able to heat through completely, so the longer the dish you use, the better. Refrigerate the dish for several hours before making the potatoes. If you don't chill the pie interior, the mashed potatoes will sink down to the bottom of the mixture and change the consistency of the dish. So put it in the fridge for at least 3 hours, though if you could leave it overnight that would give the best results. If you're really crammed for time, pop the baking dish into the freezer for 1 hour before moving on with the rest of the recipe. Preheat the oven to 350 °F (177 °C). Once you're ready to make the potatoes and assemble your cottage pie, turn the oven on so it has time to heat up. Peel and dice 2.5 pounds (1,100 g) of potatoes. Use a vegetable peeler to remove the skins from the potatoes. Dice the potatoes into 1 inch (2.5 cm) squares on a clean cutting board. Discard the skins or add them to a resealable bag to make a vegetable stock later. If you want to complete this task ahead of time, submerge the cut potatoes in a bowl of cold water to keep them from turning brown. Then drain them once you're ready to boil them. Boil the potatoes in a pot for about 15 minutes, or until they soften. Add the potatoes to a large pot and add enough water to just cover them. Turn the burner on high, and bring the water to a boil. Cook the potatoes for about 15 minutes, or until you can easily pierce a potato with a fork. You could also put the potatoes in the microwave in a bowl covered in plastic wrap. Microwave them for about 5 minutes, or until they get soft. Drain the water from the potatoes, then add the butter to the pot. Carefully drain the potatoes into a colander. Transfer the potatoes back into the hot pot, and then add 2 tablespoons (30 grams) of butter. Mix the potatoes and butter together until the butter has completely melted. Ghee is a great substitute for butter if you can't have dairy products. Add the 2⁄3 cup (160 mL) of milk and mash the potatoes. Pour the milk into the pot and start stirring and mashing everything together. Use a manual potato masher, or you could also use a ricer to get a really smooth consistency. Avoid adding in any additional liquids to the potatoes. They need to be creamy yet firm for this recipe so they don't melt down into the meat mixture. Take the meat and vegetable tray out from the fridge. Once the potatoes are mashed, remove the baking dish filled with the meat and vegetables out of the fridge or freezer. Set it on the counter near the pot of freshly mashed potatoes. Spoon the mashed potatoes overtop of the beef mixture. Transfer all of the mashed potatoes to the baking dish. Try to spread them out evenly so the thickness of the potatoes is the same across the entire surface. Use a gentle hand when spreading the potatoes so that you don't push them too far down into the rest of the dish. Take a fork and make rough lines all over the surface of the potatoes. Simply press the fork into the potatoes and drag it across them to make lines. The rougher the lines the better! The rough edges of the lines become crispy and browned in the oven, adding a nice texture to the dish. If you're interested in a pretty presentation, try making a hatched pattern across the top of the potatoes. Drizzle the potatoes with 1 tablespoon (15 grams) of melted butter. Melt the butter in a small dish in the microwave, and then carefully pour it overtop of the mashed potatoes. Use more or less butter per your preferences. For an extra decadent dish, sprinkle some grated cheddar cheese over the potatoes. Bake the cottage pie for 25 to 30 minutes, or until the top is golden. Put the baking dish into the preheated oven. Set a timer for 25 minutes, and let the cottage pie cook. Check it once the timer has gone off. If the top isn't browned, leave it in the oven for an additional 5 minutes. If the top starts to burn but the insides aren't warmed through yet, put aluminum foil over the dish while it continues baking. Let the pie rest for 5 to 10 minutes before you serve it. After you take the pie out of the oven, set it on a heat-protected surface to rest. Take this time to prepare any side dishes you want, like a fresh salad. Letting the pie rest helps the ingredients set better, and it also prevents you from accidentally burning your mouth! Save the leftovers in the fridge for 3 to 5 days, or freeze for 6 months. Within 2 hours of cooking the cottage pie, place any leftovers into air-tight containers. Keep leftovers in the fridge for no longer than 5 days, and keep them in the freezer for no more than 6 months. Put a “date made” label on your leftovers so you'll remember how long they'll be good for. 
Chop up the onion, carrot, and celery. Heat 1.5 tablespoons (22 mL) of olive oil on medium-high heat. Satué the onion, carrots, celery, and garlic for about 3 minutes. Add the beef to the pan and brown it for 5 to 7 minutes. Mix in 1/4 cup (40 grams) of flour to the beef and vegetables. Combine the rest of the ingredients with the beef. Simmer the mixture for 30 minutes, or until it starts to thicken. Put the mix into an 11 by 7 inches (28 by 18 cm) baking dish. Refrigerate the dish for several hours before making the potatoes. Preheat the oven to 350 °F (177 °C). Peel and dice 2.5 pounds (1,100 g) of potatoes. Boil the potatoes in a pot for about 15 minutes, or until they soften. Drain the water from the potatoes, then add the butter to the pot. Add the 2⁄3 cup (160 mL) of milk and mash the potatoes. Take the meat and vegetable tray out from the fridge. Spoon the mashed potatoes overtop of the beef mixture. Take a fork and make rough lines all over the surface of the potatoes. Drizzle the potatoes with 1 tablespoon (15 grams) of melted butter. Bake the cottage pie for 25 to 30 minutes, or until the top is golden. Let the pie rest for 5 to 10 minutes before you serve it. Save the leftovers in the fridge for 3 to 5 days, or freeze for 6 months. 