For the Lime Pico de Gallo: Chop tomatoes and onions and mix together in a bowl with the cilantro. Add the juice from 1/2 lime and salt & pepper to taste. Stir.
Combine the mayo and chipotle. Set aside for later.
Cut the avocados into slices or chunks
Add olive oil to pan. Season the steak with blackening or fajita seasonings then cook to desired temperature. Let cool for a minute or two, then slice for the tacos.
In taco boats, layer steak, peppers, lettuce, pico de gallo, cheese and avocado.
Top with chipotle mayo (to make it pretty, put mixture into a sandwich bag, cut off a small piece of the corner and squeeze over tacos)
*You should have some pico de gallo left over to use with chips.