Preheat oven to 375 degrees.

Prepare the marinade for your steak as the oven preheats. Combine soy sauce, tequila, lime juice, garlic, cilantro, and pepper in a ziploc bag. Add the steak and remove as much air as possible from the bag before sealing. Allow steak to marinade for at least 30 minutes in the refrigerator.

Steam corn tortillas between slightly damp paper towels by placing in the microwave for 30 seconds, or until they are flexible. Gently drape each corn tortilla over 2 bars of your oven rack. Bake tortillas for 8 to 10 minutes until they have formed crispy taco shells. Set aside.

Combine the sour cream, cilantro, and lime juice for the cilantro sour cream in a small bowl and set in refrigerator until ready to use.

Fire up your grill (or grill pan over medium-high heat)! Grill the discs of pineapple until caramelized, about 2 minutes per side. Remove from grill to a cutting board and (carefully so you don’t burn yourself!) cut the pineapple into bite-size pieces. Combine grilled pineapple, red onion, red wine vinegar, chili powder, and cayenne in a medium bowl. Set aside.

Remove steak from refrigerator and wipe off the excess marinade before cooking it on your grill (or grill pan). Cook steak until it’s reached your desired doneness.  Allow the steak to rest for at least 5-10 minutes and then slice thinly. Divide sliced steak, pineapple salsa, and cilantro sour cream among the taco shells evenly and promptly devour.