I saw this in a recipe for Turkey Tetrazini. It says you can use guar or xanthan to thicken sauces.

Turkey Tetrazini from Dana Carpenter newsletter

2tb butter
1 small onion, diced
2 cans mushrooms, drained
1 cup heavy cream
1 cup half and half
2 tsp chicken bouillon crystals
2 tb dry sherry
3/4 cup grated Parmesan cheese
1 tsp guar or xanthan (optional, will make sauce thicker)
cooked spaghetti squash, scraped into strings, (about 3 cups)
3 cups dices leftover turkey

Over medium heat, melt butter in a heavy skillet, and start the onions and the mushrooms sauteing in it. While that's cooking, combine the cream, the half and half, bouillon crystals, sherry and guar, in a blender, and blend it for just ten seconds or so, to combine. Go back and stir your veggies. When the onion is limp and translucent, transfer half of the vegetables into the blender, add the Parmesan, and blend for another 20 seconds or so to puree the begetables. Combine the cream sauce with the spaghetti, the rest of the vegetables, and the turkey, and mix everything well. Put in a 10 cup casserole that you've sprayed with non-stick cooking spray. Bake uncovered at 400 for 20 min unil bubbly.

6-8 servings. assuming 6 : 7g Carbs, trace of fiber, 24g protein, 492 cal