Step 1

Sprinkle salt, chili powder, and cumin on 1 side of the steak. Heat oil in a large skillet over high. Sear steak, seasoned side down, for 2 minutes. Flip, and cook 30 seconds longer. Remove from heat.

Step 2

Arrange onion slices on bottom of slow cooker, and top with seared steak. Spread bell pepper strips over steak, and top with salsa. Cover and cook on high for 2 hours or on low for 4 hours.

Step 3

Transfer steak to a cutting board; let stand 5 minutes. Thinly slice against the grain. Return sliced steak to slow cooker. Add fresh lime juice, and let stand 5 minutes before serving. The meat and veggies may also be held on warm in the slow cooker until ready to serve, up to 1 hour. Prepare tortillas according to package directions. Serve steak and veggies inside tortillas with desired toppings.