โ1 large loaf (1 lb) day-old challah or brioche, cut into 1-inch cubes
โ12 slices thick-cut bacon, cooked until crisp and crumbled
๐ง2 cups shredded sharp cheddar cheese
๐ง1 cup shredded Gruyere or Swiss cheese
๐ฅ8 large eggs, at room temperature
๐ฅ3 cups whole milk, at room temperature
๐ฅ1/2 cup heavy cream, at room temperature
โ1 tbsp Dijon mustard
๐ง1 tsp salt
๐ถ๏ธ1/2 tsp black pepper
โPinch of ground nutmeg
โ2 tbsp chopped fresh chives, for garnish (optional)