Lemon Chicken Potato Green Bean Casserole

INGREDIENTS

4 tbsp

butter

2 cloves

garlic, minced

small white onion, diced

4 tbsp

flour*

2 cups

milk (any fat %), warmed to not quite boiling

1 tsp

dried thyme

1 tsp

dried oregano

1 cup

grated cheddar cheese

1 cup

grated Gruyere

salt and freshly-ground black pepper

1 1/2

lbs. potatoes (I used Russet) very thinly sliced

1 lb

boneless, skinless chicken breasts, cubed

1 1/2 cups

fresh green beans, cut to 1" segments

lemon, halved and thinly sliced