Make the steak marinade. In a blender or food processor, combine the lime juice, orange juice, garlic, cilantro, salt, pepper, olive oil, and vinegar. Pulse until fully combined. Set aside.

Marinate the steak. Place the steak in the bottom of a large shallow bowl or dish. Pour the marinade over the top of the steak. Use the back of the spoon to distribute the marinade evenly. Cover the bowl tightly with plastic wrap and refrigerate for at least 1 hour.

Cook the carne asada steak. Preheat a large cast-iron skillet or frying pan. Saute on each side for about 7 minutes per side. Remove from heat and let the meat rest for 10 minutes before slicing. Alternatively, you may cook the meat on the grill for the same amount of cook time.

Slice the carne asada. Thinly slice into small pieces for taco filling and set aside.

Assemble the tacos. Slightly warm a corn tortilla and place it on a plate or work surface. On half of the tortilla, place 2 spoonfuls of prepared mashed potatoes, carne asada steak pieces, and a sprinkling of each type of cheese. Gently fold the tortilla in half. Repeat until all tortillas are filled.

Heat your oven to 200F. Place a cookie sheet lined with parchment paper in the oven. You’re going to use this to keep your tacos warm as you fry them all up.

Fry the tacos. Lightly coat the bottom of a skillet with olive oil and heat on medium-high heat. Once the oil is hot, gently place the tacos on their sides in the pan. Slightly pressing down on the edges to help keep them closed. Fry the tacos for about 45 seconds per side and then transfer them to a paper towel-lined plate. Repeat the process until all the tacos are fried. Add more oil to the skillet as needed. Once each batch of tacos has drained on the paper towel for a few minutes, transfer them to the oven to keep warm. 

Serve warm with your favorite fixings. Ideas include salsa macha, consomé, Oaxaca cheese, lettuce and guacamole.