This over-the-top sandwich is especially good because of the layer of crispy croutons and the pungent roasted lemon and anchovy dressing that’s drizzled on the grilled chicken filling. Slideshow: More Sandwich Recipes
In a large bowl, stir 2 tablespoons of the olive oil with the lemon juice, rosemary and minced garlic. Add the chicken thighs, turn to coat and cover with plastic wrap. Refrigerate for at least 2 hours or overnight.
Preheat the oven to 425°. Wrap the head of garlic in foil, then set on a foil-lined baking sheet and bake for 40 minutes. Arrange the lemon halves cut side down on the baking sheet and bake for 10 minutes more. In a small bowl, toss the bread cubes with 1 tablespoon of the olive oil and spread on the baking sheet; bake until toasted, about 8 minutes. Let the garlic, lemon halves and croutons cool for 5 minutes.
To make the dressing, squeeze the garlic cloves from their skins into a small bowl and mash until smooth. Squeeze the flesh from the roasted lemons into the bowl and add any juices from the baking sheet. Add the remaining 1/2 cup of olive oil, the crème fraîche, cheese and anchovies and stir until smooth. Season with salt and pepper.
Light a grill or heat a grill pan over moderately high heat. Season the chicken thighs with salt and pepper and grill, turning once, until cooked through, 12 to 14 minutes. Transfer the chicken to a plate and let rest for 10 minutes.
To serve, arrange 2 romaine leaves on the bottom half of each toasted bun. Top each with 2 chicken thighs. Spoon the dressing generously over the chicken and then sprinkle the croutons and capers on top. Close the sandwiches and serve immediately with more dressing on the side.
The dressing can be refrigerated for up to 3 days.
Pair these sandwiches with a bold, lemony Sonoma County Chardonnay.