To make this dish, the squid is first cooked with a whole onion in a pressure cooker, and this takes only about half an hour for the squid to become wonderfully tender. While this is happening, you can boil the potatoes and roast the bell peppers (directly over a gas burner, turning with tongs, until blackened and blistered). These are all gathered in a baking dish with crushed garlic cloves and baked until the potatoes turn nice and crispy.