In a pot, melt your butter.
Add in your onions and sweet peppers, sauteing for 3-5 minutes.
When the onions are clear, pour in your cream and stir.
Whisk in your xanthan gum. If it doesn’t thicken too much, add in another ? teaspoon.
Once your cream is thick and is bubbling, slowly stir in your cheddar cheese - one small handful at a time. Make sure it melts before adding more.
Do the same thing with the Gruyere cheese, one small handful at a time.
Add salt and pepper to taste.
Serve with veggies, low-carb crackers, or throw on some low-carb nachos.