Step 1
Melt the butter and olive oil in a large pot or Dutch oven. Add the onions and cook for about 10 minutes until tender and just beginning to brown.
Step 5
Add to a blender (or use an immersion blender) to blend the soup until creamy. Taste and season with salt and pepper. If the soup tastes bitter, you can add a touch of honey or maple syrup to balance the flavor. You can also add a touch of half and half to balance this flavor if your turnips turn out to be on the bitter side.