Heat margarine in a pot and cook onion until soft and translucent, about 3 minutes. Add mushrooms and 1 can of chicken broth and cook for 5 minutes.
Add sweet potato and second can of chicken broth to the pot. Stir in bacon bits, garlic salt, thyme, and bay leaf, and bring to a boil. Reduce heat and simmer soup until sweet potato is soft, about 15 minutes.
Remove and discard bay leaf. Puree soup using an immersion blender until smooth. Stir in half-and-half and Gouda cheese and mix until well blended.
