- 2 grapefruits
- 1-pound salmon fillet, cut into 4 pieces
- Salt and pepper, to taste
- 1 tablespoon high-heat oil
- 2 tablespoons minced shallots
- 1 teaspoon finely grated fresh ginger
- 3 tablespoons mirin
- 1 tablespoon white or yellow miso, to taste
- 3 to 4 tablespoons unsalted cold butter, cut into pats
Remove 1 teaspoon zest from a grapefruit. Juice 1 grapefruit and set aside ¼ cup juice. Remove peel and cut remaining grapefruit into segments. Set aside.
Pat salmon dry; season with salt and pepper. Heat oil in a large sauté pan over medium-high heat. Sear salmon, flesh-side down, until golden brown, 2 to 3 minutes. Turn salmon over and finish cooking, reducing the heat if needed. Transfer to a warm plate.
In the same pan, sauté shallots and ginger for 1 to 2 minutes. Add grapefruit zest, reserved juice and mirin. Cook until liquid is reduced to about 2 tablespoons. Stir in miso.
Turn off the heat, leaving the pan over the warm element. Whisk in butter, 1 pat at a time, adding each new piece before the previous piece completely melts. Occasionally lift the pan from the element to cool the mixture (if the sauce gets too hot, it will separate). Pour sauce over warm salmon, garnish with reserved grapefruit segments and and serve immediately.