Preheat the oven to 450F. Line a baking sheet with parchment paper.
Place salmon filets on the prepared baking sheet. Drizzle with 2 tbsps of olive oil, cumin, and garlic powder plus a healthy pinch of salt and pepper. Bake for about 20-25 minutes.
Change oven temperature to broil then broil salmon until the tops are crispy and the inside is opaque and flakes with a fork, about 3-5 minutes.
While the salmon is baking, combine tomatillos, tomato, red onion, jalapeño, cilantro, lime juice, remaining 1 tbsp of olive oil plus a healthy pinch of salt and pepper in a medium bowl. Toss until well combined.
Divide romaine between plates. Top each plate with one salmon filet and a large scoop of chunky tomatillo salsa.