Blend tomatoes, serrano pepper, onion, and garlic cloves. If the blender does not run add water, one or two tablespoons.
In a small pot, add oil and pour the sauce, add the salt and leave until it starts to simmer, lower the heat and leave for 5 more minutes.
On a plate crumble the drained tofu. Remove any excess liquid. Mix with the chopped onion and salt.
In an extended dish or bowl put two or three handfuls of tortilla chips, lather some sauce and finish with the crumbled tofu and avocado slices.
Notes
The only trick here is to buy the best tortilla chips that you can find I usually buy the baked and organic ones.
You want thick corn tortilla chips with a lot of flavors. I use baked tortilla chips, which work perfectly with the salsa Roja, and red sauce. But maybe you will have a bit of a trial-and-error situation until you find the perfect brand.
Serve immediately. If you want to store, store separately. The sauce has to be stored in the fridge and the toppings.