Start by roasting 4-5 tomatoes in the oven at 400F for 20 minutes or so.
Saute 1.5 roughly chopped onions and 3 whole, peeled garlic cloves in a dollop of oil over medium heat. When the onion starts to turn brown (approx. 6-8 minutes) add the mixture to a blender or food processor along with the roasted tomatoes. Combine well.
Add the noodles to a saucepan along with a dollop of oil. Cook the noodles over medium heat for 3-5 minutes or until some of them are turning darker brown. Add the tomato-onion mixture from the blender and combine well with the noodles. Let this mixture cook for a couple minutes and then add 8 cups of stock. (When using homemade stock, I usually add at least 1/2 teaspoon of salt and some freshly cracked black pepper at this point.)
Bring the soup to a boil and then reduce heat to a simmer and let it cook for 10-20 minutes, or until the noodles are cooked through.
Take a final taste for seasoning, adding more salt if necessary. You can optionally add a pinch of Mexican oregano at this point.
Serve immediately and store leftovers in an airtight container in the fridge.