Preheat the oven to 425 degrees. Mist 2 large baking sheets with
cooking spray. In a small baking dish, mix together 2 tablespoons
lime juice with garlic, chili powder, cumin, and 1 teaspoon olive oil.
Add salmon and turn to coat; let sit.
In a medium bowl, toss corn, bell pepper, poblano pepper, and
onion with remaining 2 teaspoons olive oil. Transfer corn mixture
to one of the baking sheets; spread into a single layer.
Remove salmon from marinade and arrange on second baking
sheet. Drizzle corn mixture with remaining salmon marinade.
Season salmon and corn with salt and black pepper to taste and
roast 8 to 10 minutes, until fish is just cooked through and
vegetables are tender.
Mix together sour cream, cilantro, and remaining lime juice. Season
with salt to taste. Spoon corn onto plates and add salmon. Drizzle
cream over fish.