Ingredients:

Remoulade sauce
1/2 cup mayonnaise
1 tablespoon fresh lemon juice
1 garlic clove, pressed
1 teaspoon (packed) minced fresh Italian parsley
1 teaspoon grated onion
1 teaspoon anchovy paste
2 hard-boiled large egg yolks
1/4 cup extra-virgin olive oil
2 tablespoons drained capers

Burgers
1/4 cup olive oil
2 tablespoons tarragon vinegar
2 small bay leaves, broken
4 6-ounce ahi tuna steaks (each about 1 inch thick)

Nonstick vegetable oil spray
4 4-inch square crusty artisanal rolls or squares of focaccia, split horizontally

Methods:

For sauce: Whisk first 6 ingredients in bowl to blend. Using fine grater, grate in egg yolks. Whisk in oil, then capers. Season with salt and pepper.

For burgers: Combine oil, vinegar, and bay leaves in large heavy-duty resealable plastic bag. Shake to blend. Add tuna. Seal bag; turn to coat. Chill at least 1 hour and up to 2 hours, turning bag occasionally.

Spray grill rack with nonstick spray and prepare barbecue (medium-high heat). Brush cut sides of rolls with some of tuna marinade. Grill rolls, cut side down, until golden, about 2 minutes. Transfer rolls to work surface. Grill tuna, with some marinade still clinging, until slightly charred but still pink in center, about 2 1/2 minutes per side.

Place tuna on roll bottoms. Top with dollop of sauce, then roll tops. Serve, passing remaining sauce separately.