Pre-heat oven to 450 degrees F. Line a baking pan/dish with parchment paper. Place fish on parchment, skin side down. Season fish with salt and pepper and roast for 10 minutes.
Optional: Place tomatillos, onion, and jalapeno in a microwave safe bowl and heat (covered) for 3 minutes. Alternately, steam stovetop for 4-5 minutes.
Place steamed vegetables with cilantro, salt, cumin, and lime juice in blender or vitamix and puree.
Serve chile verde over fish