Dice beef strips into small cubes. Place in medium bowl and toss with 1/2 tsp. olive oil and taco seasoning.
Heat remaining oil in a medium-large sauté pan over high heat. Add beef to the pan in a single layer and lower to medium high heat. Allow meat to sear for 1-1/2. Stir and cook for an additional 1-2 minutes until cooked through.
Divide lettuce leaves between 2 plates. Top each lettuce leaf with beef, tomatoes and avocados. Serve immediately.