Challah Breakfast Casserole

Ingredients (10)

• 1 pound sweet Italian sausage
• 2 tablespoons olive oil
• 1 large shallot, chopped
• 1 pound challah bread, toasted
• 8 large eggs
• 2 1/2 cups milk
• 1 cup heavy cream
• 8 ounces gouda (or Gruyere) cheese, grated
• Salt and pepper
• Fresh scallions, garnish