Partially freeze pork; thinly slice across grain into bite sized strips. Place pork in a plastic bag set into a bowl.
Combine salsa, lime juice, beer, garlic, cilantro, cumin, red pepper and black pepper. Pour over pork; seal bag. Marinate in refrigerator for 3 to 4 hours.
Prepare Easy Chunky Guacamole: Halve, seed, peel and cube 2 avocados. Combine avocados, lemon juice and salsa in a bowl. Cover and chill. (can be kept up to 24 hours in fridge).
Wrap tortillas in foil. Heat in a 350°F oven for ten minutes to soften.
Drain pork and set aside, reserving marinade.
Add enough water to marinade to equal 1 1/2 cups. Place in a saucepan and bring to a boil. Add rice. Remove from heat and let stand, covered, for 5 minutes.
Meanwhile, spray a skillet with nonstick coating; heat over medium heat. Add half of the pork. Stir-fry 4 minutes or until no longer pink. Remove from skillet using a slotted spoon; drain liquid if necessary. Repeat with remaining pork.
Spread pork and Easy Chunky Guacamole on tortillas. Roll up and serve with rice.