Melt the butter or coconut oil over medium heat. Once melted, add the garlic and onions and sautee for five minutes or until soft.
Add the cubed turnips and rutabagas and sautee for an additional minute.
Add the 3 cups of water, the bouillon cubes, thyme, and salt and bring to a boil.
After the mixture comes to a boil, turn to medium low heat and simmer for 20 minutes, stirring occasionally.
Once the root vegetables are very soft, remove from heat and use an immersion blender to puree thoroughly, or carefully transfer the soup in to a blender and puree in batches.
Serve in bowls, garnished with grated cheese of your choice if any, and salt and pepper to taste.