Season chuck steaks on both sides with chili powder, onion powder, cumin, garlic powder, salt, and black pepper.

Heat 2 tablespoons vegetable oil in a large skillet over medium-high heat. Cook chuck steaks in the hot oil in batches until browned, about 5 minutes per side. Transfer to a slow cooker.

Heat remaining 1 1/2 teaspoon vegetable oil in the same skillet. Add 2 green onions and garlic; cook and stir until browned but not burnt, 3 to 4 minutes. Remove from heat; chop garlic coarsely and return to the skillet.

Whisk tequila, lime juice, lemon juice, orange juice, and ginger together in a bowl. Mash in kiwi using a fork. Stir in green onion-garlic mixture and chipotle sauce. Pour over chuck steaks in the slow cooker.

Cook on Low until steaks are fork-tender, 6 to 8 hours.

Transfer chuck steaks to a cutting board; shred with 2 forks. Mix in 2 raw green onions.

Pour cooking liquid from the slow cooker into the skillet. Simmer over medium heat until reduced and thickened into a sauce, about 10 minutes. Stir in shredded steak; simmer until most of the sauce is absorbed, about 5 minutes.

Preheat oven to 350 degrees F (175 degrees C). Coat the bottom of a 9x13-inch baking dish with 1/4 of the pasilla chile sauce.

Spoon shredded steak mixture into tortillas. Wrap up and place seam-side down, close together, in the baking dish. Pour remaining pasilla chile sauce over tortillas. Sprinkle mozzarella cheese and chives on top.

Bake in the preheated oven until cheese is melted and bubbly, 20 to 30 minutes.