Thinly slide the steak across the grain, discarding any fat, bone, or gristle.
Combine the lime, orange, grapefruit, vinegar, garlic, spies and oil in a food processor blender and blend until smooth. Toss the steak with the marinade and refrigerate for a few hours.
Working in batches, heat the corn tortillas in a dry pan until slightly browned on each side. Set aside.
Remove the steak from the marinade and pat dry. Heat a nonstick skillet or grill pan over high heat, and working in batches, cook the steak pieces until just barely cooked through, about 30 seconds per side.
To serve, place some shredded lettuce on a tortilla, top with a couple pieces of steak and a slice of avocado. If desired, sprinkle with a little hot sauce.
Recipe by Cooking With MicheleĀ® at https://cookingwithmichele.com/2024/09/citrusy-steak-tacos/