Preheat the broiler. Put the quartered tomatoes, sliced onion, and whole garlic cloves onto a roasting tray, spreading out evenly. Drizzle with plenty of olive oil and season well with salt and pepper and sprinkle with cilantro sprigs. Broil until everything is nicely charred, about 10 minutes (you want lots of deep rich color so don't be afraid if some of the edges get pretty black).
This is truly delicious. I don’t have an abundance of tomatoes this year but what I have are going into this salsa, pizza sauce and roasted tomato soup. All to enjoy this winter. Another plus for this salsa is it is so nice and thick it stays on your chip. Not sliding off before you can get it to your mouth! I made the recipe as written, using a variety of tomatoes. My jalapenos are a little small and I would like just a wee bit more heat in a few jars, but that is the only adjustment I will make.
This salsa traditionally has Chiles de Arbol, tomatoes, garlic, salt and water, but some cooks like to add tomatillos (the medium size tomatoes with a husk), like I do in this recipe. This is a very spicy salsa, but you can adjust the spiciness to fit your own taste by reducing the amount of Arbol peppers. This salsa goes well with “Tacos al Pastor”, too. Most Taquerias in Mexico City that sell Tacos al Pastor offer this salsa to top your tacos with. Some people know this salsa as Salsa de Chile de Arbol and others as Salsa Taquera.