For the remoulade, combine all ingredients in a bowl. Taste, and adjust the seasonings to your preference. Set aside.

Preheat the broiler to high and spread butter on both sides of the bread. Broil the bread just until golden on both sides.

Preheat a large skillet with ¼ inch oil to medium-high heat for frying. Toss the scallops with the cornstarch and salt. When the oil is very hot (test it with just 1 scallop, it should sizzle), add the scallops in 1 layer. Fry the scallops for about 4 minutes, flipping when golden, until browned on all sides. Drain the scallops for a minute on paper towels.

To serve, layer a piece of bread, some veggies, a pile of scallops, and some remoulade. Top with a lemon wedge and serve!