Mix olive oil, leeks, mushrooms, onions, and sausage together in 10-inch nonstick round roasting pan. Season with salt and pepper.
Place pan in Bravo and roast at 360°F for 6 min., pausing halfway to stir.
While sausage mixture is cooking, combine eggs, heavy cream, milk, and white cheddar in a bowl. Mix until eggs are incorporated; set aside.
When sausage mixture is done, add bread cubes to egg mixture in bowl. Mix with sausage mixture in pan. Mix well to combine. Cook at 300°F for 20-25 min.
