Preheat oven to 350F and bring a large pot of salted water to a boil.

Place the butter in a medium saucepan set over medium-low heat. Once the butter is melted, add the white rice flour and mustard powder and whisk to combine. Cook for five minutes whisking constantly. The color of the roux will change and that's okay.

Pro tip: Place the milk in a pyrex and microwave for 5 minutes while the butter and rice flour cook. Keep an eye on the milk to make sure it doesn't spill over in the microwave. This will save you some time whisking over a hot stove.

After 5 minutes, increase to medium heat and add the milk and bay leaf to the butter mixture. Whisk constantly and bring to a boil. Reduce the heat and simmer for 10 minutes and remove the bay leaf.

Meanwhile, add your gluten-free pasta to the boiling water and cook according to package directions to al dente.

Off heat add the cheddar cheese to the sauce and stir to combine. Taste for seasoning, I usually start with 1 tsp salt and go from there. Add the drained gluten-free macaroni and stir to combine.

In a medium bowl, add the gluten free bread crumbs, parmesan cheese and melted butter. Stir to combine.

Pour the macaroni and cheese into an 8 by 8 baking dish and top evenly with the bread crumb mixture. Cook time is 30 minutes. Rest for 5 minutes after it comes out of the oven.

Enjoy!