Ingredients Meat & Poultry Beef Recipes Ground Beef Recipes Tacos 2.7 (3) 1 Review By Martha Stewart Test Kitchen Martha Stewart Test Kitchen The recipes developed by our test kitchen team have undergone a rigorous process of development and testing, ensuring that every element is optimal, from ingredient amounts to method and cooking time. This process includes triple-testing recipes to ensure they meet our high standards. The many stellar cooks and food editors who have been part of our team include Sarah Carey, Lucinda Scala Quinn, Jennifer Aaronson, Shira Bocar, Anna Kovel, Greg Lofts, Riley Wofford, Lauren Tyrell, and Lindsay Leopold. Editorial Guidelines Updated on June 29, 2019 Print Rate It Share Share Tweet Pin Email Yield: 12 To make homemade taco shells, you will need a taco mold, or follow the instructions given below (see Note) on how to construct your own mold with aluminum foil. Ingredients 2 avocados, pitted and peeled Juice of 2 limes ¼ cup chopped fresh cilantro, leaves 1 teaspoon coarse salt, plus more to taste ¼ teaspoon freshly ground pepper, plus more to taste 1 tablespoon olive oil 1 yellow onion, cut into ½-inch dice 1 pound ground sirloin 1 teaspoon dried oregano ¼ teaspoon ground cumin 12 corn tortillas 8 ounces cheddar cheese, grated ¼ head iceberg lettuce, shredded ½ cup sour cream Tomato Salsa Tomato Salsa Directions Make the guacamole: In a medium bowl, mash avocado with the back of a fork until desired consistency. Stir in lime juice and half the chopped cilantro, and season to taste with salt and pepper. Set aside. Make the beef filling: In a large skillet over medium-high heat, heat oil. Add onion, and cook until translucent, about 10 minutes. Add sirloin, oregano, cumin, 1 teaspoon salt, and 1/4 teaspoon pepper. Cook, stirring occasionally, until meat is cooked through, about 4 minutes. Cover to keep warm, and set aside. Make the shells: Preheat the oven to 350 degrees. Wrap 4 tortillas in aluminum foil, keeping them flat. Place foil packet and taco mold, if using, in oven for 5 minutes to heat. Remove packet and mold from oven; remove tortillas from the packet, and drape each over a taco form. Return to the oven, and cook until crisp, about 10 minutes. Remove from oven, and let sit on mold for 2 minutes until slightly cooled. Repeat with the remaining tortillas. In separate bowls, set out the beef filling, grated cheese, shredded lettuce, guacamole, sour cream, and salsa. Give each person 2 taco shells, and have them fill their own. Rate it Print