On a preheated comal or griddle, place the tomatoes, chiles, onion and garlic. Dry roast the ingredients for 25 minutes. Remove the garlic after 10-12 minutes and set aside.
Add 1/4 cup of oil to a small skillet and heat to medium heat. After 2 minutes, add the chile guajillo. It will fry quickly and become aromatic. turn as needed and cook for just a few seconds per side. Remove from oil and set aside.
Peel the garlic and add to the blender. Also add all the dry roasted ingredients and the fried chile guajillo. Add 2 cups of water and 4 tsp of knorr bouillon(chicken flavor). Blend on high until smooth. Using a wire mesh strainer, strain the blended sauce into a bowl. Set aside.
In a deep skillet, add 3 tablespoons of oil and preheat at medium for 3-4 minutes. Add the onions and carrots. Season lightly with salt and pepper. Saute for 6-8 minutes.
Add the strained sauce to the pot. It should come to a boil quickly. Reduce heat slightly and cook for 7-10 minutes. Taste for salt.
Add 2 more cups of water, epazote, bay leaves oregano and cilantro. Also add the 2 cups of zucchini. Stir well to combine and continue cooking for 5 minutes. Finally add in the shrimp. Stir gently, cover and continue cooking for 5-6 minutes. Take the soup off the heat and let sit for 5 minutes.