Avocado sauce: Mash one of avocados. Chop the other avocado and mix them with the mashed avocado in a bowl. Stir in the vinegar and olive oil. Finely chop the red and green peppers, tomato, and the onion and add to the avocado. Mince the garlic and add to the mixture. Season the guasacaca with salt, pepper to taste.
Preparation of steak: Keep the meat outside at least 1 hour before grilling. Put salt and pepper just before grill them. Heat the skillet well before putting steaks on. Grill the steaks on the skillet as you like with low heat.