Heat 1/2 tablespoon vegetable oil in a small saucepan over medium heat. Add half of the garlic and cook, stirring, until golden, about 1 minute. Add the beans and bring to a simmer. Remove from the heat, sprinkle with the cheese and cover to keep warm.
Heat 1 tablespoon vegetable oil in a skillet over medium-high heat. Add the pork, the remaining garlic, half of the red onion, the cumin, cayenne and 1/2 teaspoon salt. Cook, stirring, until the pork is browned, about 5 minutes; transfer to a bowl with a slotted spoon. Heat the remaining 1 tablespoon vegetable oil in the skillet. Add the bell pepper, zucchini and 1/4 teaspoon salt and cook until crisp-tender, about3 minutes. Return the pork to the skillet; add a splash of water, and salt and pepper to taste.
Fill the tortillas with the pork and vegetable mixture. Serve with the beans. Sprinkle with the remaining chopped onion.