Heat a non-stick skillet or another pan*** over medium heat. Cook the diced bacon until it renders its fat and gets crispy. Remove to a paper towel lined plate and set aside.
Leave about a teaspoon of the bacon fat in the pan, remove the rest. Sauté the diced shallots until softened.
Add the heavy cream, bring to simmer (adjust heat to low or medium-low as necessary, you want to see gentle bubbles, do not allow the cream to boil). Simmer for about 5 minutes, then add the Parmesan and gently stir it in. Simmer a bit longer until the sauce thickens to your desired consistency.
Season liberally with salt and pepper to offset the sweetness of the cream (taste). Fold in the bacon bits and serve (use with pasta etc.) immediately. Sprinkle with red pepper flakes and parsley to taste.
