Place the tomatoes, green chillis, onion, garlic, coriander and cumin in a large saucepan. Cook over medium heat until the mixture comes to a boil. Reduce heat to low and simmer until the onion is soft, about 45 to 60 minutes.
Meanwhile, heat a large frypan over medium-high heat and stir in the chorizo. Cook and stir until the chorizo is crumbly and evenly browned. Drain and discard any excess grease.
Preheat an oven to 180 degrees C. Stir together the ricotta cheese and eggs. Set aside.
To assemble, spread 1/3 of the tomato sauce in the bottom of a 20x30cm baking dish. Spread the chorizo over the tomato sauce. Pour 1/2 of the remaining sauce over the meat and sprinkle 1/2 of the grated cheese over the top of the sauce. Arrange a layer of lasagne lengthwise over the cheese. Spread the ricotta cheese mixture over the lasagne and place another layer of lasagne over the ricotta. Top with the remaining tomato sauce and grated cheese. Cover with foil: to prevent sticking, either spray foil with cooking spray or make sure the foil does not touch the cheese.
Bake in a preheated oven for 30 minutes. Remove foil and bake until the top is browned, about 15 to 30 minutes.
I use ground chorizo meat, not the stuffed sausages, but they'll do okay, too. If you can't find chorizo, try substituting 1 kg of lean beef mince and a couple packets of taco seasoning. It ain't the same, but it'll be edible!