Slow-Roasted Salmon with Mexican Creamed Corn

unsalted butter, at room temperature

garlic, grated

Zest and juice of 1 lime

Kosher salt and freshly ground pepper

Nonstick cooking spray

skin-on salmon fillet (in one piece), preferably sockeye

medium shallots, chopped

small tomatillos (about 8 ounces), husked, rinsed and quartered

ears corn, kernels cut off (about 4 cups)

Fresno chile pepper, seeded and chopped

Mexican crema or sour cream

fresh cilantro, chopped