Cook the pasta as directed on the package. Set aside.
In a large saute pan (I use my cast iron pan), cook bacon for 5-8 minutes, until crispy. Remove half the bacon fat and add chopped mushrooms.
Cook mushrooms for another 5 minutes and add butter. Once butter melts, whisk in flour to make a roux. Whisk in yogurt and cream and stir until it thickens, over low heat. Toss with pasta and lemon zest and serve.