Traditional Mexican Ground Beef Tacos 1 lb lean ground beef 12 taco shells 1 1/2 cups shredded American or Cheddar cheese 2 cups shredded lettuce 2 tomatoes, chopped Heat oven for 300°F. In a saucepan, brown onion over medium heat. After 5-10 minutes, add ground beef and cook until beef is cooked, stirring frequently.
While cooking beef, prepare other ingredients: mix shredded lettuce, tomatoes and cheese, add salt pepper to taste. After the beef is cooked, place taco shells into the oven and heat them at 250°F for 3-5 minutes. To assemble, layer beef on taco shells first, and then add all the mixed veggies and cheese equally on each taco.