Briny uni and acidic lemon, mixed with smoky paprika and rich butter, combine to make an extraordinary flavored butter to top oysters before roasting. If shucking oysters isn’t your thing, you can ask your fishmonger to do the job for you.
Heat the broiler on high. Combine butter, uni, lemon zest and juice, oregano, red-pepper flakes, smoked paprika, garlic, and salt in a medium bowl. Using an electric mixer, beat the butter mixture until well combined. Set aside.
Spread rock salt on a rimmed baking sheet. Carefully nestle opened oysters in salt so they remain upright. Top each oyster with 1 tablespoon uni butter; broil until butter melts and browns on edges, 3 to 5 minutes. Serve immediately with lemon wedges.