Preparation

1. Cook pasta according to package directions, and reserve 1/2 cup of the cooking water.
2. In a large skillet over medium-high heat, cook the bacon until crisp. Remove bacon to a paper towel-lined plate to drain. Do not remove fat.
3. Add sausage and onions and cook until sausage is starting to brown and onions are translucent. Add mushrooms and cook until soft and onions have started to caramelize.
4. Add beer and scrape any bits from bottom of pan. Cook until liquid reduces to 1/4 cup. Remove from heat and keep warm.
5. In a medium saucepan over medium heat, melt the butter. Once melted, whisk in flour and cook for 2 minutes, whisking constantly.
6. Slowly stir in milk. Bring to a simmer, reduce heat to medium-low and continue cooking until mixture thickens, stirring often, about 5 minutes.
7. Stir in mustard and cheese and remove from heat. Add apple cider vinegar, salt and pepper, and stir until incorporated.
8. Add sausage mixture and sour cream and stir until well combined. Toss with pasta, adding reserved pasta cooking water if mixture is too thick.
9. Adjust seasoning as needed, top with snipped chives, and enjoy!