Chicken Salad with Lemon, Rosemary and Toasted Almonds

Ingredients

• 1 onion, quartered
• 4 large garlic cloves, crushed
• 2 stalks celery, chopped
• 1 carrot, peeled and chopped
• ½ teaspoon peppercorns
• Kosher salt
• 4 bone-in skin on chicken breast halves
• ½ cup sliced almonds
• ½ cup Mayo (preferably Duke’s), plus more as desired
• 1 tablespoon Dijon mustard
• 2 celery, thinly sliced
• 1 bunch scallions trimmed and thinly sliced
• 1 tablespoon The Usual, plus more as desired
• 2 tablespoons finely chopped fresh rosemary
• Finely grated zest of 1 lemon
• Freshly squeezed juice of ½ lemon, plus more to taste