2 tablespoons olive oil
1 pound skinless cod fillets (about 1/2-inch thick), thawed if frozen and patted very dry
2 tablespoons all-purpose flour
1/4 teaspoon kosher salt
1/4 teaspoon freshly ground black pepper
1 medium lemon
1/4 cup capers, drained
3 tablespoons unsalted butter
3 cloves garlic, smashed
Torn fresh flat-leaf parsley leaves, for serving
Heat the oil in a large nonstick frying pan over medium heat until shimmering. Meanwhile, sprinkle the cod evenly with the flour, salt, and pepper on both sides. Add the cod fillets to the pan and cook until golden-brown and cooked through, about 3 minutes per side. Remove to a plate and cover with foil to keep warm.
Increase the heat to medium-high and squeeze in the juice of the lemon. When it begins to bubble, add the capers, butter, and garlic and swirl over the heat until the butter is completely melted and fragrant, about 1 minute. Spoon the sauce over the fish, sprinkle with the parsley, and serve immediately.