Gigantes  
Big beans are probably onion-free anyway, but I like them, which is reason enough in itself, and they are useful for mopping up the remains from the Mexican pork stew recipe. They are also extremely easy to prepare.

1/3 tin of butterbeans
1/3 tin of chopped tomatoes
2 tsp tomato puree mixed with a little hot water
1 fat clove of garlic
4 sprigs of thyme
Lemon, salt, fresh ground black pepper.

Throw the main ingredients into a small heavy saucepan, add the thyme (leaves stripped from the stem), and lemon juice, salt and pepper to taste. Leave it to simmer gently for half an hour to reduce the liquid and thicken it, then serve with some bread to mop up the juice. They're great cold the next day, too.