Step 1

Heat the grill over high heat. Place the skirt steak onto a sheet pan and pat dry. Season both sides well with a pinch of salt. Let sit for 30 minutes at room temperature.

Step 2

For the salsa, lightly coat the whole tomatoes, half of red onion, and serrano pepper with olive oil. Grill for about 3 minutes until slightly charred, turning each ingredient continuously to char on all sides. Transfer the ingredients to a cutting board and let cool.

Step 3

Roughly chop the tomatoes, red onion, and serrano. Add them to a food processor along with the garlic and cilantro. Pulse until finely chopped. Transfer the salsa to a bowl and stir in the lime juice. Season with salt to taste.

Step 4

For the avocado crema, wipe out the food processor. Add in the avocados, garlic, serrano pepper, cilantro, and lime juice. Process until smooth. Season with salt to taste.

Step 5

Pat the steak dry again and lightly coat with oil. Grill the skirt steak over the hottest part of the grill for about 3 minutes, or until a nice crust forms. Flip and continue to cook to your desired doneness, about 3 more minutes for medium (time will vary depending on the thickness of your skirt steak). Transfer the steak to a cutting board and let rest for 5 minutes. Thinly slice the steak against the grain.

Step 6

To assemble the tacos, spoon the avocado crema onto a warm tortilla. Add a few slices of steak and a generous spoonful of salsa. Top with the queso fresco and any extra cilantro.