Cook bacon in frying pan over medium heat, add sage after a couple minutes, then add garlic for the last minute before bacon is crisp and done. Remove ingredients from pan - do not clean the pan - chop the bacon, toss with sage and garlic, and set aside.
Put the pan back over medium heat, add onions and cook for about 5 minutes until onions turn translucent and smell heavenly. Add squash, season with salt and pepper, and cook for about 35 minutes, stirring occasionally, until squash is soft.
In the meantime, cook your favorite pasta in salted water, save a cup of the pasta water, drain, and set aside.
When the squash is soft, add the pan contents in a blender, add heavy cream, and puree. Again, do not clean your frying pan in between. Just put the blender contents back in the pan.
Add cooked pasta to the pan, along with ½ c cheese and about ½ c pasta water. Keep stirring and watch the sauce thicken up, with the cheese melting. Season with salt, freshly cracked pepper, and ground nutmeg. If the sauce is too thick, add some more pasta water; if it’s too runny, cook a couple minutes to let some liquid evaporate.
Divide into four pasta bowls, top with the chopped bacon-garlic-sage mixture, and serve.