In a large sauté pan over medium heat, add a dollop of oil to coat the bottom.
Add your diced bell peppers and red onion. Season with salt and pepper. Sauté until cooked through.
Add the block of extra firm tofu and use a spatula (or back of a fork) to crumble into pieces that resemble ground meat.
Add the taco seasoning and liquid smoke. Stir to combine. Taste and adjust seasonings as necessary.
Optional: Adjust the heat to a medium-high temperature to continue cooking the tofu. Use the back of a spatula to press the tofu into the pan and allow it to sit for a minute or so or until the bottom layer of tofu is slightly burnt. Remove from heat when done. This will help add flavor and texture to the dish.
Preheat a separate pan to low-medium heat and add your tortilla. Sprinkle a generous amount of vegan cheese over half of the tortilla, then add a few scoops of the tofu mixture, followed by more vegan cheese. Fold over the other side of the tortilla to make a semi-circle.
Allow the tortilla to cook on both sides until it's golden brown and the vegan cheese has melted (may be helpful to cover with a lid). Repeat until all of your quesadillas have been made.
Garnish with fresh cilantro (optional) and pair with your favorite additions like vegan sour cream, salsa or guacamole. Enjoy!