In a large non stick saute pan, saute the onion over medium heat until lightly brown and soft. Put the cooked onion in the food processor with drained beans, garlic, taco seasoning, Picante sauce, and ricotta cheese. Pulse until it is a chunky puree.
Put the mixture back in the saute pan and season to taste with salt and pepper. Heat until hot and bubbling.
Spray the corn tortillas with cooking spray on both sides. Place them directly on the oven rack and bake for 10 minutes in a preheated 350 degree oven.
To serve, place the corn tortilla on a plate and top with the bean mixture. Add the chopped onion. I like the crunch from the onion.
Top with some lettuce.