Add first 12 ingredients and 4 cloves of minced garlic to a mixing bowl and whisk together. Pour over the steak, and refrigerate covered for 8-12hrs. Onion Salsa: Dice onion and mix 1/2 with 1/4c cilantro and 1/4c lime juice. set aside. Salsa Caliente: Place tomatoes, 1/2 an onion and 4 cloves garlic on baking sheet. Bake at 400F for 20-25mins. Add to mixing cup and blend well. Set aside. Add marinated steak to a heavy skillet and cook on med-high for 10-12mins until cooked to desired doneness. Tortillas: Add 2c of maseca and 1.5c water to a mixing bowl and mix well by hand. Roll dough into golfball sized balls and flatten with tortilla press. Add oil to skillet and bring up to med-high heat. Toast torillas for 3-4mins per side. Finishing: Add cooked meat, onion salsa, salsa caliente, avocado slices, cheese if desired and a squeeze of lime to the tortillas. Enjoy!