Chicken Salad, Walnuts, Roasted Tomatoes, Pickled Red Onions, and Frisée on Multigrain Bread

Ingredients

• 2 tbsp. extra-virgin olive oil
• 10 cloves garlic, unpeeled
• 8 ripe tomatoes, cored and halved
• 6 sprigs thyme
• Kosher salt and freshly ground black pepper, to taste
• 1⁄2 cup red wine vinegar
• 2 tbsp. plus 1/3 cup sugar
• 1 tsp. red pepper flakes, finely chopped
• Pinch of curry powder
• 1 small red onion, thinly sliced into rings
• 1⁄3 cup white wine vinegar
• 1⁄4 cup yellow mustard seeds
• 6 cups Chicken Stock
• 5 basil leaves
• 4 sprigs flat-leaf parsley
• 2 sprigs oregano
• 4 skin-on bone-in chicken breasts (about 2 3/4 lbs.)
• 1⁄2 cup chopped toasted walnuts
• 1⁄2 cup mayonnaise
• 1 tbsp. fresh lemon juice
• 1 rib celery, finely chopped
• 8 slices dense multigrain bread
• 1 head frisée, trimmed