Spanish omelette

About $1.20 a portion for a thick wedge of potatoes and onion slow-cooked in olive oil and set with eggs. It tastes far richer than its shopping list: golden outside, soft in the middle, and just as good cold the next day stuffed into a sandwich. The one real expense is the olive oil, and much of it can be strained off and used again. Serve it with a sharp green salad or some roasted peppers and nobody will guess what it cost.