Ingredients

Ingredients

For the beef filling:

• 1 tablespoon neutral oil, such as canola, grapeseed, or vegetable
• 1 small yellow onion, diced (1/2 cup)
• 1 pound lean ground beef
• 2 tablespoons tomato paste
• 1 (1-ounce) packet or 3 tablespoons taco seasoning
• 1 cup water

For the tacos:

• 12 crunchy taco shells
• 1 beefsteak tomato, diced (1 cup)
• 1 small ripe avocado, diced (optional)
• 1/4 medium head iceberg lettuce, shredded
• Shredded cheddar, Monterey, Colby, or Mexican blend cheese
• Sour cream

Instructions

1. Arrange a rack in the middle of the oven and heat the oven to 350°F.
2. Heat 1 tablespoon neutral oil in a large skillet over high heat until shimmering. Add 1 diced small yellow onion and cook, stirring occasionally, until translucent and slightly softened, about 4 minutes. Add 1 pound lean ground beef and cook, breaking it up into small pieces with a wooden spoon, until cooked through and browned, 6 to 8 minutes. Add 2 tablespoons tomato paste and 1 (1-ounce) packet taco seasoning. Cook until fragrant and the tomato paste is slightly darkened, about 2 minutes.
3. Add 1 cup water and scrape up the browned bits from the bottom of the skillet, and bring to boil. Reduce heat to maintain a simmer and cook until the liquid has almost completely evaporated, about 10 minutes. Meanwhile, prepare the toppings.
4. Arrange 12 crunchy taco shells in a single layer on a rimmed baking sheet and bake for 5 minutes.
5. Divide the taco meat between the shells (about 2 heaping tablespoons each). Serve with 1 diced beefsteak tomato, 1 diced small ripe avocado if using, 1/4 shredded medium head lettuce, shredded cheese, and sour cream for topping.

Recipe Notes

Make ahead: The beef filling can be made up to 2 days ahead and refrigerated in an airtight container. All of the toppings except for the avocado can be prepared up to 1 day in advance and refrigerated in separate in airtight containers. Reheat the beef in the microwave or over medium heat on the stovetop.

Storage: If not eating all of the tacos in one sitting, don’t fill the shells before serving. Instead, assemble as you go. Refrigerate leftover taco meat and toppings in separate airtight containers. The taco shells can be stored in an airtight container at room temperature.