2 teaspoons canola oil
1 (1-pound) yellowfin tuna fillet, about 3/4 inch thick
3/4 teaspoon kosher salt
1/4 teaspoon black pepper
8 (6-inch) corn tortillas
2 ears of sweet corn, boiled and cut off cobb
1/4 cup reduced-fat sour cream
1 peeled avocado, cut into 16 slices
Heat a medium skillet over high heat. Add oil to pan; swirl to coat. Pat tuna dry with a paper towel. Sprinkle tuna with salt and pepper. Add tuna to pan; cook 2 minutes on each side or until desired degree of doneness. Transfer tuna to a cutting board; cut across the grain into 1/4-inch-thick slices.
Warm tortillas according to package directions. Divide tuna evenly among tortillas. Top each taco with 1 tablespoon salsa, 1 1/2 teaspoons sour cream, and 2 avocado slices. Serve immediately.