Heat avocado oil in a skillet over medium heat. Add chopped tomatillos, yellow onion, minced garlic, and jalapeño, cook until charred for 5–7 minutes. Add water to thicken for 3 minutes, then blend with cilantro, lime juice, oregano, salt, and half an avocado until smooth. Refrigerate.

In a bowl, combine skirt steak with lime and orange juice, chopped cilantro, smoked paprika, onion powder, black pepper, and ground cumin. Marinate for at least 1 hour, preferably 6 hours in the fridge.

Preheat grill or skillet over medium-high heat for 10 minutes. Grill steak for 4 minutes on each side until golden crust forms and reaches 125°F for medium-rare. Add green onions to grill last 2 minutes.

Transfer steak to a cutting board and let it rest for 5 minutes. Warm corn tortillas on the grill for 1 minute each side.

Dice the rested steak and place on warm tortillas. Top with avocado salsa, diced white onion, and cilantro. Serve immediately with grilled green onions and lime wedges.