For frozen scallops, remove them from the package and place them, in one layer, on a wire rack set over a plate or baking sheet, cover with a sheet of parchment paper and transfer to the refrigerator to thaw. When ready to cook, proceed as follows:
For fresh or thawed scallops, place scallops on a large plate that has been lined with a double layer of paper towels. Salt liberally and allow to rest for 5 minutes. Using more paper towels, pat the scallops on all sides as dry as possible. Sprinkle lightly with salt and pepper and set aside while preparing the griddle and butter.
Add the butter to a small dish and melt in the microwave. Remove and add the grated garlic and fresh thyme leaves. Reserve and keep warm.
Heat the oil in a cast iron griddle or a heavy-bottomed skillet set over high heat until it just begins to smoke. Working in batches, add some of the scallops spacing them an inch or so apart, cook for 1½ minutes to a rich brown. Turn the scallops with tongs and cook the other side for 1 minute. Just before removing the scallops from the pan, spoon the melted garlic-thyme butter over the top. Transfer to a paper towel lined plate and repeat with the remaining scallops.
To serve, add a 2 tablespoon pool of the romesco sauce to a dinner plate, place 4 scallops on the sauce and garnish with fresh thyme sprigs and lemon wedges.
Notes
Scallop size matters. U-10 scallops means fewer than 10 scallops per pound. Each one weighs about 2 ounces.Adjust cook time for smaller scallops. If using smaller sizes, sear for about 1 minute per side to avoid overcooking.Use dry scallops. “Dry” means they haven’t been treated with preservatives and will sear properly without releasing excess liquid.Don’t crowd the pan. Give the scallops space to brown evenly and develop that golden crust.Serve immediately. Scallops are best right off the pan when they’re buttery and tender.