Mushroom Panzanella

Ingredients

• CROUTONS
• 1 lb loaf crusty Italian bread, sliced in 3/4-inch pieces crusts removed
• 6 tablespoons unsalted butter
• 3 tablespoons minced garlic
• 1 tablespoon finely minced fresh thyme
• 1/2 cup finely grated parmesan cheese
• salt
• freshly ground coarse black pepper
• ROASTED ONION PUREE
• kosher salt
• 3 whole onions, peeled
• 1 cup low sodium chicken broth or 1 cup water
• MUSHROOMS
• 1/4 cup olive oil
• 1 lb mushroom, cleaned and thickly sliced
• TO ASSEMBLE
• 6 tablespoons olive oil, plus more for drizzling
• 3 tablespoons red wine vinegar, plus more for drizzling
• 1/2 cup finely grated parmesan cheese, plus more for garnishing
• 1 tablespoon finely mince fresh thyme
• 2 ounces Baby Spinach or 2 ounces baby arugula
• 1/4 red onion, very thinly sliced
• 3/4 cup celery heart (sliced thinly on the diagonal, plus some more of the chopped leaves)
• salt