Half and half is simply half whole milk and half cream. In the UK, they call it half cream. According The Kitchn, half and half typically has a 10 to 12 percent fat content, which, it stands to reason, means it's less fatty than cream and fattier than milk.
Dogs can eat peas safely. Peas are a good source of potassium, zinc, iron and several vitamins. Depending on the size of the dog, 1 or 2 tablespoons of peas is recommended. The dietary fiber in peas also helps overweight dogs feel full thereby reducing the dog's intake.
Just like every other Is it safe for dogs to eat X?. It all depends on how much. Our hounds love mackerel in tomato sauce and all sorts of pasta in tomato sauce. They regularly get given leftover pasta as a treat and mackerel as a regular part of their diet. The sauce may contain onions and garlic, but in such tiny amounts that they'd have to eat gallons of sauce for it to be harmful. As for tomatoes. Yes, they do contain some alkaloids, but in very small amounts, far too small to be harmful.