This is a fragrant and rich topping for grilled oysters that you can adjust cook-time for very different outcomes.
The Lemon-Herb Butter can be prepared in advance and either frozen or refrigerated until needed. We have found that a melon-baller tool helps proportion and release the butter.
½ cup/115 grams unsalted butter (1 stick), cut into pats
1 ounce fresh parsley leaves (about 1 packed cup), roughly chopped
1 ounce fresh basil leaves (about 1 packed cup)
6 medium garlic cloves, finely minced or pressed through a garlic press
1 lemon, zested and juiced
Kosher salt and freshly ground black pepper
Before you get started, decide if you will (1) pre-heat the oysters to help open them or if will you will (2) shuck them raw to roast.
Using heat certainly makes the job easier, but one must wait for oysters to cool before this can be done safely. This method also adds cooking time and this may not be preferrable.
The alternative does require shucking skills. Our preference is to shuck the oysters raw and plate them for heating right from the start. Then you can simply apply the butter and monitor until done.
The above decision lies in how you would like to cook and interact with guests. If you are hesitant about being stressed and shackled to cooking duties, consider prepping the oysters ahead of time like we recommend with the butter. Once shucked and placed on the tray, they can be covered and refrigerated upto 24 hours until you are ready to cook.
Prepare the garlic-herb butter: In a food processor, combine the butter, parsley, basil, garlic, lemon zest and juice, a large pinch of salt and a few grinds of pepper. Process until the herbs are finely chopped and there are no large chunks of butter remaining, about 30 seconds total, stopping to scrape down the sides of the processor with a rubber spatula a few times as needed. Transfer the mixture to a storage container and refrigerate, or freeze. If you freeze days in advance, be sure to thaw before you start to cook. If you are cooking soon, transfer to an oven-safe saucepan.
Pre-heat grill. See the pro-tip below.
Place plated oysters on the grill. Cover and start to cook.
Portion the garlic-herb butter for each oyster with a spoon. If your butter is cool, use a melon baller to portion. If you want to melt the butter as you grill, use a large spoon to mix ingredients (as they can stratify if left alone) and portion into each oyster. This can be done off-grill or as the oysters cook.
Cook, uncovered, until the sauce mixture is bubbling hot, about 1 minute. Return the oysters to the foil-lined baking sheet or another service tray and serve immediately. Do warn guests that the oysters and the shells are hot.
Cooking Surfaces: The liquor from oysters has salt and if spilled into your grill, can hasten its decay. To protect your grill and to have the best outcome, prepare a a grill-safe tray (baking sheet, broiling pan, disposable aluminum pan). Use sections of cut aluminum foil, 2X the size of your tray crumpled down to fit and fill the base of the tray. The crumpled foil will act like a nest and support the cupped side of the oyster preventing them from tipping over and spilling their precious liquor. If pre-heating, you will need to transfer them one by one to another sheet as they open so they can cool before handeling. Use tongs to do this, or just wait for all to open. Once cool, use an oyster knife or similar kitchen tool to cut the top abductor muscle, discarding the top shell. Next, cut the bottom abductor so the oyster is completely free from its shell. Return the oyster to the foil next, cup side down. Press into the foil so it remains stable as the tray is moved around. See our shucking guide for more tips.
Finishing: A little service showmanship can be applied as you present your oysters. Use a small chefs torch to just hit the top of the oysters, slightly browning the butter and charing some of the imbedded herbs.
Rare or Well-Done? Regardless of the recipe, cooking oysters by time is tricky depending on the size of the oyster, the relative heat of the oven or grill, personal preference and when the oysters are dressed with ingredients during cooking. Oysters, like most seafood, can over-cook quickly so use a time to help you check-in but use your eyes. For "rare" we look for the gills of the oyster to start to ruffle. A rare oyster also has much of its original liqour preserved. A medium oyster will be fully ruffled and about 1/2 of its liquor has boiled off, dramatically changing the baseline salt-profile and texture of the oyster. A well done oyster will have no liquor but is still hydrated. The oyster is also shrinking through this progression. Like most living things, it is mostly water to begin with, so when all of the water has cooked off, the oyster will be dry and will be dramatically smaller and start to change color. We consider oysters over-done at this point but there are many who prefer their oysters over-done.