Butternut Squash Strata with Leeks, Chicken Sausage and Mushrooms

Ingredients

• 3 cups butternut squash, peeled and cut into 3/4" cubes.
• 1/2 t. black pepper
• 6 cups hearty bread, cut into 1-inch cubes
• 3 large leeks
• 2 garlic cloves, minced
• 12 oz. mushrooms, cremini or white, sliced
• 12 oz. cooked chicken apple sausage, sliced
• 1 T. flour
• 5 T. mild olive oil
• 4 large eggs
• 2 cups milk
• 1 t. dried thyme
• 1/4 cup shredded Parmesan cheese
• 1 cup shredded Swiss cheese