Brussel Sprouts Gratin

INGREDIENTS

slices thick-cut bacon

2 lb

brussels sprouts, trimmed and halved (cut into thirds or quarters if very large—you want the pieces to be roughly the same size)

1/2

yellow onion, finely diced

3/4 tsp

kosher salt, divided

1 tbsp

unsalted butter

2 tbsp

all-purpose flour

1 1/2 cups

2% milk

1 tbsp

chopped fresh thyme (or 1 teaspoon dried thyme leaves)

1/4 tsp

black pepper

ground nutmeg (optional)

1/2 cup

freshly grated Gruyère cheese, sharp white cheddar cheese, or a similar fully flavored, melty cheese

1/4 cup

whole wheat bread crumbs

Olive oil cooking spray