01 - Combine tomatillos, cilantro, green chili, onion, garlic, lime juice, and salt in a blender or food processor. Blend until completely smooth. Taste and adjust seasoning as needed. Set aside until assembly.
02 - Heat olive oil in a large skillet over medium heat. Add chopped onion and sauté for 2 minutes until softened. Add minced garlic and jalapeño, continue cooking for 1 minute until fragrant.
03 - Add ground beef to the skillet. Cook while breaking up meat with a spatula until browned and cooked through, approximately 6-7 minutes. Stir in cumin, smoked paprika, chili powder, oregano, salt, and black pepper. Cook for 2 additional minutes, mixing thoroughly to coat beef evenly with spices. Remove from heat.
04 - Heat tortillas in a dry skillet on each side until pliable, or wrap in foil and warm in a 300°F oven for 10 minutes.
05 - Fill each warm tortilla with spicy beef mixture. Top generously with salsa verde, avocado slices, crumbled cheese if desired, and fresh cilantro. Serve immediately with lime wedges for squeezing.