Step 1

Prick sweet potatoes all over with a fork. Microwave on High until soft, 10 to 12 minutes.

Step 2

Meanwhile, heat oil in a large skillet over medium-high heat. Add beef, chili powder, cumin, garlic powder, onion powder, chipotle and salt; cook, breaking the beef up into small pieces with a wooden spoon, until browned and no longer pink, 4 to 6 minutes. Whisk water and tomato paste in a measuring cup; add to the pan and stir to coat the mixture. Stir in 1/2 cup cheese.

Step 3

Halve the sweet potatoes and mash the flesh a bit with a fork. Top each half with 1/2 cup of the beef mixture, 2 tablespoons cheese, 1/4 cup lettuce and 1 tablespoon pico de gallo.