Lemon Caper Mayonnaise
3 egg yolks
½ cup extra virgin olive oil
1 small shallot, finely chopped
2 tbsp drained capers
2 tbsp chopped parsley
Zest of half a lemon
2 tbsp lemon juice (about half a lemon)
Salt and pepper
Grilled Flounder
8-16 skinless flounder fillets, depending on size
One recipe lemon caper mayonnaise (see above)
Salt and pepper
Lemon wedges for garnish
Make the Mayonnaise
Place the egg yolks in the base of a blender and top with a little salt and pepper. With the blender running, very very slowly drizzle in the olive oil. You may want to put the olive oil in a pitcher or measuring cup with a spout to make it easier to pour slowly. The egg-oil mixture will emulsify (thicken) as you pour. Once all the oil is added, stop the blender and add the remaining ingredients. Pulse a few times, scraping down the sides of the blender in between, until the mayonnaise is well combined – it should still have some texture. (You can also do this all by hand using a metal bowl and a whisk – just make sure to add the oil very slowly and very finely chop the other ingredients.) Transfer to a small bowl, taste for seasoning and adjust as needed, and refrigerate until ready to use.
Grill the Flounder
Preheat your grill to medium-high. Generously rub the filets with the mayonnaise, reserving at least half for serving. Sprinkle lightly with salt and pepper. Lay the filets in a grill basket* or on a sheet of tin-foil and grill 1-3 minutes per side, depending on the size of your filets. The fish will shrink slightly as it cooks and should be firm to the touch and very slightly browned. Serve immediately with lemon wedges and the remaining mayonnaise.
* I find flounder is too thin and delicate to grill without the added support of a basket, which allows the fish to still get some smokiness and charring from the grill, without the risk of falling through the grates. If you don’t already have a grill basket though, by all means just use a sheet of tin foil.