Potato, baby spinach and griddled spring onion recipe Trim the spring onions and remove any yellowing or imperfect leaves. Brush them with olive oil. Heat a griddle pan and cook the onions on both sides. Start off on a high heat to get charring marks and then turn down the heat and cook until they are tender (but not so far that they are floppy). Put the warm potatoes, spinach leaves and spring onions into a broad shallow bowl. Season and drizzle on as much dressing as needed - it should be generous without drowning the salad. Put the rest into a jug and offer on the side.