Mushroom, Bacon, and Swiss Strata

INGREDIENTS

12 oz

ciabatta, cut into 1-inch cubes (about 7 cups)

2 tbsp

butter

2 cups

chopped onion

2 8 ounce packages

presliced mushrooms

Cooking spray

1 1/2 cups

shredded reduced-fat Swiss cheese

center-cut bacon slices, cooked and crumbled

3 cups

1% low-fat milk

1 1/2 cups

egg substitute

2 tsp

chopped fresh thyme

1/2 tsp

freshly ground black pepper

1/4 tsp

salt

Thyme sprigs (optional)