Cook beef in a large nonstick skillet over medium-high heat until browned, stirring to crumble. Add garlic, bell pepper, and plantain; cook for 3 minutes. Add tomatoes and next 4 ingredients (tomatoes through black pepper); cook 5 minutes, stirring occasionally.
Heat the tortillas according to package directions. Spoon 1/2 cup meat mixture onto each tortilla; top each with 1/4 cup lettuce, and roll up.