3 1/2 tablespoons unsalted butter
salt and freshly ground black pepper to taste
1/4 cup lemon juice only
1 to 3 teaspoon Dijon-style mustard
In a medium skillet over medium-high heat, heat the butter and lemon juice until the butter melts. Continue to cook, swirling the pan almost constantly, until the butter turns light brown, about 2 minutes. Remove from the heat and whisk in the mustard. The sauce won’t be smooth. Season lightly with salt and pepper. Serve on any vegetable or mild, white fish.