Keep oysters and mussels well chilled on ice until just before serving. If oysters are not yet shucked: hold oyster flat-side up, insert oyster knife at hinge, twist to pop, run blade under adductor to free, then remove top shell, loosen oyster from bottom shell leaving juices (liquor) intact. For mussels: steam in a covered pot with a splash of water until shells open (about 4–6 minutes), discard any that remain closed. Cool immediately in ice water, then transfer to shell halves or small serving spoons with some cooking liquid removed so they sit flat.

Mignonette

Make mignonette

Finely mince the shallot until very small. In a small bowl combine red wine vinegar, champagne vinegar, minced shallot, cracked black pepper, sea salt and sugar. Stir until salt and sugar dissolve; add cold water to slightly mellow acidity and balance texture. Taste and adjust: it should be bright and tangy with a hint of shallot crunch. Chill at least 15 minutes so flavors marry. Keep refrigerated until serving.

Makrut Lime Oil

Infuse oil

Place grapeseed oil in a small saucepan with the finely grated makrut lime zest. Warm gently over the lowest heat for 6–8 minutes — the oil should be warm but not simmering or smoking (60–70°C / 140–158°F) — to release aromas without cooking bitterness. Alternatively, for a cold infusion, combine oil and zest in a jar and let sit in a cool dark place for 12–24 hours.

Finish oil

Remove from heat and let cool to room temperature. Strain through a fine mesh sieve or cheesecloth into a bowl to remove zest solids, pressing gently to extract oil. Stir in the makrut lime juice and a pinch of fine sea salt. Taste and adjust: add an extra 1/2 tsp juice if you want a brighter pop. Transfer to a small squeeze bottle or pourer and refrigerate; bring to near-room temperature before serving (oil may thicken slightly when cold).

To Serve

Arrange crushed ice or rock salt on a serving platter to create a stable bed. Nestle oysters and mussels into the bed so they sit level. Place small bowls of mignonette and makrut lime oil on the platter, or dispense directly onto oysters at service.

To plate each oyster or mussel: spoon about 1/2 tsp mignonette onto the meat (do not drown—just a bright accent). Add 2–3 drops (about 1/8 tsp) of makrut lime oil over or around the shellfish for an aromatic, citrusy finish. Garnish with a small sprinkle of micro herbs or a few chopped chives and offer lemon/lime wedges on the side.

Serve immediately while shellfish are cold and fresh. Discard any leftovers after 2 hours. Advise diners to taste the oyster first, then experiment with mignonette and oil to appreciate the contrast.