Creamy Green Bean Casserole from Scratch

INGREDIENTS

large onion*

1/2 cup

all-purpose flour

3/4 cup

Panko breadcrumbs*

1/2 tsp

salt

1/4 tsp

ground black pepper

large egg

1 tbsp

milk

1 tbsp

+ 1 teaspoon salt, divided

1 lb

fresh green beans, rinsed, trimmed and halved

2 tbsp

unsalted butter

ounces mushrooms, sliced into halves or quarters*

1/2 tsp

ground black pepper

2 cloves

garlic, minced (minced roasted garlic is great here)

2 tbsp

all-purpose flour

3/4

cup (180ml) chicken or vegetable broth

and 1/4 cups (300ml) half-and-half*