Cook bacon in a frying pan over medium heat till crisp. Remove from pan, then chop once cool to enough to handle.
To the same pan, add the onion and mushrooms. Cook and stir over medium heat till softened.
Cook butternut squash noodles according to packet instructions. Drain and add to the pan along with the chopped bacon and spinach leaves. Toss together and cook till spinach is wilted. Remove from heat and serve.
Garlic can be added, if liked. Only 131 calories per portion.