In a bowl, combine the orange juice, chile powder, oregano and 1 teaspoon salt. Place steak in a large glass or ceramic container and coat all over with the marinade. Cover with plastic wrap and refrigerate at least 4 hours, preferably overnight.
To make the salsa, light a grill, keeping a small area unlit for indirect heat. Grill pineapple over direct heat until charred on both sides, 3 to 5 minutes a side.
Toss the tomatillos, onion, jalapeños and garlic with olive oil, remaining 1/2 teaspoon salt and black pepper. Place the garlic over indirect heat, cut-side down, and grill until charred and somewhat tender, 6 to 10 minutes (do not turn). Grill the onion, cut-side down over direct heat, until well charred, 3 to 5 minutes (do not turn). Grill the tomatillos and jalapeños over direct heat on both sides until they are tender and blistered, 1 to 3 minutes a side.
When cool enough to handle, peel onion and coarsely chop it and tomatillos and jalapeños. Squeeze the garlic from the peel and mash with the flat side of a knife, then chop. In a bowl, combine vegetables, half the garlic and the pineapple. Toss in cilantro and season with a squeeze of lime juice and salt and pepper to taste.
Grill steak until done to taste, about 2 to 4 minutes each side. Let rest for 10 minutes, then spread the remaining garlic on top.
Carve steak against the grain, serve with the salsa and lime wedges