1 cup coarse fresh breadcrumbs, preferably sourdough
Kosher salt and freshly ground black pepper
2 pounds 1½–2 whole branzino or trout, butterflied
Lemon wedges (for serving)
oven to 450°. Whisk oil, mustard, garlic, and thyme in a small bowl.
Using your fingertips or a rubber spatula, mix in breadcrumbs, squeezing
or pressing to saturate bread, until evenly coated; season with salt
up fish and place, skin side down, in a large ovenproof pan or on a
rimmed baking sheet; season with salt and pepper. Top with breadcrumb
mixture, pressing to adhere. Roast until breadcrumbs are golden brown
and fish is cooked through, 10–15 minutes.