Melt your butter in a deep pot on medium.
Add in the green onions, mushrooms, and carrots.
Saute the veggies for 3-5 minutes.
Sprinkle your xanthan gum over the vegetables.
Quickly add in your cream and stir.
It should start thickening immediately, but keep on the heat until it starts to bubble.
Place your shirataki noodles in a casserole dish.
Stir the cream mixture into the noodles.
Mix in your cheddar cheese and flaked tuna.
Optionally, top your casserole with almond flour
Bake at 350°F for 35 minutes.