GRILLED CHICKEN PAN BAGNAT

Steps:

• Using meat mallet, pound chicken breasts between sheets of plastic wrap to 3/4-inch thickness. Combine 1/3 cup oil, 2 tablespoons lemon juice, herbes de Provence, and half of garlic in large resealable plastic bag. Add chicken to bag; shake to coat with marinade. Chill at least 2 hours and up to 6 hours.
• Prepare barbecue (medium-high heat). Remove chicken from marinade; shake off excess. Sprinkle chicken with salt and pepper. Grill chicken until cooked through, about 4 minutes per side. Cool. Cut chicken on diagonal into 1/2- to 3/4-inch-thick slices.
• Whisk anchovy paste, remaining 4 tablespoons lemon juice, and remaining garlic in small bowl. Gradually whisk in remaining 3/4 cup oil. Season dressing to taste with salt and pepper.
• Cut both bread loaves horizontally in half. Pull out and discard soft interior crumbs from top halves, leaving 1/2-inch-thick shell; drizzle 1/4 cup dressing over inside of each top. Drizzle 1/4 cup dressing over inside of each bottom half; sprinkle 2 tablespoons capers in each. Divide chicken, tomatoes, onion, and lettuce between sandwiches. Cover with tops, pressing to compact. Wrap sandwiches in foil, then place heavy skillet or food cans on top to weigh down. Refrigerate at least 2 hours. (Can be made 1 day ahead. Keep refrigerated. Let stand at room temperature 1 hour before serving.)
• Cut each sandwich into quarters and serve cold or at room temperature.
• A dried herb mixture available at specialty foods stores and in the spice section of some supermarkets. A combination of dried thyme, basil, savory, and fennel seeds can be substituted.