Toast 3 guajillo chiles in a hot, dry cast-iron skillet over medium heat, about 1 minute per side.
In the same skillet, heat 1 Tbsp [15 ml] oil over medium-high heat. Add 1 cup [145 g] of diced white onion and 2 cloves of smashed garlic and cook until golden, about 5-7 minutes. Turn off the heat. Transfer the chiles, onions, and garlic to a blender. Add the tomatoes and blend until smooth.
Bring the pot back to medium-high heat. Add the remaining oil and pour in the tomato puree. Cook, stirring frequently, until the puree is dark red and thick like tomato paste, about 6-7 minutes. Add 6 cups [48 oz] chicken broth, epazote, and reduce to medium-low simmer for 15 minutes. Before serving, taste and season with salt and remove the epazote.
Pour 2-inches of vegetable oil into a 3-4 quart pot. Heat the oil over medium-high heat to 350°F. Fry the tortilla strips in small batches using a wire skimmer or slotted spot to stir the tortilla until golden brown, about 2-3 minutes. Using the skimmer or slotted spoon, transfer the tortillas to a paper toil to drain and season with salt.
Serve the soup in bowls with tortilla chips, cotija cheese, crema, avocado, lime, cilantro, and chile oil.