Sausage Stuffed Mushrooms

Name: Sausage Stuffed Mushrooms
Ingredients: 1 tablespoon extra-virgin olive oil, one turn of the pan; 24 large gourmet stuffing mushroom caps, stems removed and reserved brushed with damp towel; Salt and pepper; 1 1/2 teaspoons extra-virgin olive oil, half a turn of the pan; 3/4 pound sweet bulk Italian sausage; 4 cloves garlic, chopped; 20 stems mushrooms, finely chopped; 1 rib of celery and green, leafy top from the heart of the stalk, chopped; 1/2 small onion, chopped; 1/2 small red bell pepper, seeded and chopped; 1 (10-ounce) box chopped frozen spinach, defrosted and squeezed dry; 3 slices white bread, toasted and buttered, chopped into small dice; 1/3 cup grated Parmigiano or Romano, 2 handfuls