Ingredients

2 garlic cloves

1 piece fresh ginger (1 inch long)

1/2 cup smooth peanut butter

1/4 cup plus 1 tablespoon soy sauce

1/4 cup plus 1 tablespoon rice vinegar

1 tablespoon light-brown sugar

1/4 teaspoon red-pepper flakes

1 1/2 pounds flank steak

2 pounds broccoli (about 2 heads)

4 scallions

2 tablespoons vegetable oil

Coarse salt

Preparation

Marinate steak: Peel garlic; peel and slice ginger. Place both in a blender with peanut butter, 1/4 cup soy sauce, 1/4 cup vinegar, sugar, red-pepper flakes, and 2 tablespoons water. Blend until smooth. Place steak in a resealable plastic bag or shallow dish; add all but 1/2 cup sauce and refrigerate. Cover and store reserved sauce at room temperature.

Prep broccoli: Cut florets from broccoli (reserve stalks for another use); cover and refrigerate.

Broil steak: Heat broiler, with rack set 4 inches from heat. Lift steak from marinade; place on a broilerproof baking sheet. Broil until medium-rare, 8 to 10 minutes. Transfer to a large plate, and cover loosely with aluminum foil; let rest, 5 to 10 minutes.

Cook broccoli: While steak is broiling, thinly slice scallions, keeping whites and greens separate. In a large skillet, heat oil over medium. Add broccoli, scallion whites, and 1/4 cup water; season with salt. Cover skillet, and cook, tossing occasionally, until broccoli is just tender, 8 to 10 minutes. Uncover; add remaining tablespoon soy sauce and tablespoon vinegar. Cook, tossing, until liquid is evaporated, 1 to 2 minutes. Mix in scallion greens.

To serve, thinly slice steak across the grain; serve with broccoli and reserved peanut sauce.