Heat fat or oil in a large pan over medium heat. Add onion and garlic; cook and stir until softened and onion is nearly translucent, about 3 minutes. Stir in cumin and crushed red pepper. Add beans and bean cooking liquid or stock. Season to taste with salt and freshly ground black pepper. Cook and stir until beans are heated through and begin to break down. Transfer bean mixture to food processor and pulse until beans reach desired consistency and return to pan. Or mash beans with potato masher. Serve.