Avocado Bearnaise with Citrus Flank Steak

From: Chef Erik Osol, Element 116, New Haven, CT. Yield: 8 servings, 2 cups Bearnaise sauce.

3 lb. beef flank steak

as needed, citrus marinade (recipe follows)

2 Mexican Hass Avocados

2 tsp. white wine vinegar

2 small chopped shallots (½ cup)

¼ cup avocado or safflower oil

2 Tbsp. chopped fresh tarragon

½ tsp. salt

¼ tsp. ground black pepper

Citrus Marinade:

1 Tbsp. grated orange peel

½ cup orange juice

2 tsp. grated lemon zest

2 tsp. grated lime zest

3 Tbsp. lemon juice

3 Tbsp. lime juice

1 Tbsp. avocado or safflower oil

2 tsp. honey

⅛ tsp. crushed red pepper flakes

For citrus marinade: Combine marinade ingredients.

Place steak in shallow glass baking dish. Pour citrus marinade over steak; turn steak several times to coat. Cover; set aside at room temperature for at least 15 minutes, up to 1 hour, turning occasionally.

Preheat grill or broiler.

For Mexican Avocado Bearnaise: Cut avocados lengthwise in halves; twist to separate. Remove pits by striking lightly with knife blade and twisting. With a spoon, scoop flesh from shells. In blender or food processor, puree avocados with vinegar and 2/3 cup water. Transfer to bowl; fold in shallots, oil, tarragon, salt and pepper. Cover tightly and set aside.

Remove steak from marinade. Grill over medium heat, 5-9 minutes per side, until thermometer reads 125°F for medium-rare, 135°F for medium, or until steak is cooked to desired degree of doneness. Season steak with salt and pepper. Let stand 5 minutes; slice on diagonal. Serve with Mexican Avocado Bearnaise.