Make the homemade adobo sauce by adding all of the sauce ingredients to a small bowl and whisk to combine. Season with salt to taste.
To make the marinade, crush the garlic cloves with 1/4 teaspoon salt and pepper in a mortar with a pestle. Then add the remaining ingredients and continue to crush them with the mortar and pestle until they’re all combined.
Place steak in a bowl or deep sided dish and pour the marinade over the top. Massage the steak marinade into the meat and let it marinate at 30 mins at room temperature or up to 24 hours in the refrigerator.
In a large skillet over medium-high heat, heat 3 tablespoons olive oil until shimmering. Add the marinated steak to the skillet and cook until golden brown on both sides, flipping the steak halfway through cooking until medium-rare/medium stage (130°-140°F, 62°C internal temp).
Transfer the cooked steak to a cutting board to let the steak rest for 10-15 minutes. Once the steak has rested, cut it into bite-sized pieces.
Serve with guacamole, Pico de Gallo, and white rice (see additional options below). Garnish with chopped fresh cilantro. Store leftovers in an airtight container.
Notes
Calories are approximate and are calculated for 1/6 of the recipe using top sirloin steak.