Drain and press tofu with a tofu press or put a towel on top of tofu and a heavy object like a cast iron skillet on the towel and let the water drain out for at least 15 minutes.
Heat olive oil in pan and add chopped onions. Cook until translucent.
Add minced garlic. Cook 30 seconds longer.
Crumble the tofu and add to the onion. Cook for about 5 minutes, until starting to brown.
Add serrano pepper and red pepper. Cook until crisp tender.
Add black beans, spices, tomatoes and spinach. Cook until the spinach is wilted.
Place tofu scramble on a tortilla. Fold over sides of tortilla and roll away from you making a tight burrito. If you fill the tortillas with too much mixture, it will be harder to roll.