Recipe from Mama Me Gluten Free (dot) com
Projected time, start to finish, a little over an hour
1/3 cup unsalted butter, plus a little extra
1/3 cup brown rice flour
3 cups milk
1/2 cup sour cream
4 ounces cream cheese, cut into pieces
2 tsp. kosher salt
Pinch ground nutmeg
1 1/2 tsp. dry mustard
Pinch cayenne pepper
1/4 tsp. black pepper
4 cups shredded Colby jack cheese
1 pound gluten-free elbow macaroni or shells, cooked al dente according to package (I used Tinkyada, and always use the energy-saving method. It works best)
2 slices fresh bread (I used Udi's multi-grain), broken into small pieces
Preheat oven to 350 degrees. Grease 3-quart baking dish and set aside.
Cook pasta according to package, drain and set aside when finished (you might want to lightly toss in a little olive oil). You'll want to keep the pasta a little al dente, so check it several minutes earlier than the package says to cook it for.
While pasta is cooking, combine 1/3 cup of butter and brown rice flour in a large saucepan over medium heat. Whisk until smooth, then slowly add milk. Continue to stir with whisk until mixture is smooth and thickened.
Add sour cream and cream cheese, whisking in until combined and smooth again.
Add salt, nutmeg, mustard, cayenne and black pepper. Whisk lightly until mixed well. Stir in shredded cheese. Season more to taste if necessary.
Add macaroni to cheese mixture and gently mix together. Pour into baking dish.
In a small bowl, melt a tablespoon or two of butter and toss with bread pieces. Sprinkle over top of macaroni.
Bake for 35-40 minutes, or until bubbling nicely.