Gluten-Free Green Bean-Mushroom Casserole with Panko-Style Fried Onion Rings

INGREDIENTS

3 cups

white rice flour

1 1/2 cups

tapioca flour

3/4 cup

potato starch

1 tbsp

xanthan gum

1 1/2 tsp

salt

Butter or gluten-free cooking spray, for greasing

Canola oil, for frying

1/4 cup

crushed gluten-free rice cereal

1 tsp

salt

large onion, sliced thinly into rings

Salt

1 lb

green beans, trimmed

2 tbsp

unsalted butter

8 oz

fresh mushrooms, sliced

Pepper

3/4 cup

chicken broth

3/4 cup

heavy cream

1/2 tsp

chile powder