Place the sliced peppers and onions on a sheet pan. Season with 2 tsp BBQ Rub Sweet & Smoky, salt, pepper, and 2 tbsp olive oil.
Place the seasoned flank steak on top of the veggies.
Bake at 450°F for 12 minutes.
While we wait for the steak, in a medium-sized bowl, combine Greek yogurt, lime juice/zest, garlic, chopped jalapeño, olive oil, BBQ Rub Sweet & Smoky, and salt. Mix well, and refrigerate to allow the flavors to meld.
Flip the flank steak and cook for an additional 5 minutes.
Once done, let the flank steak and veggies rest for 5 minutes.
While resting, cut the avocados, and squeeze a little lime juice to prevent browning.
Slice the flank steak against the grain.
Place a few strips of veggies, flank steak, and a dollop of cilantro lime dressing on each lettuce cup. Enjoy your Flank Steak Fajitas in crisp lettuce cups with a tangy, creamy cilantro lime dressing!