INSTRUCTIONS
    
        
            1        
        
            Cook pasta according to package directions and reserve 1 cup of the pasta water for sauce.        
     
    
        
            2        
        
            Meanwhile, in a large sauté pan, cook bacon over medium until golden and crisp, about 8-10 minutes. Remove bacon from pan, set aside and leave about 2 Tbsp of the bacon fat in pan.        
     
    
        
            3        
        
            Over medium-high heat, sauté the shallots and Brussels sprouts, seasoning generously to taste with salt and pepper, until just tender and starting to brown in spots. (You may have to add a little olive oil if pan seems dry.)        
     
    
        
            4        
        
            Add vinegar and mustard and toss to combine, scraping the bottom of the pan.        
     
    
        
            5        
        
            Over medium-high heat in the pot that you cooked the pasta in, toss the cooked drained pasta, Brussels sprout mixture, and 1 cup of pasta water until the liquid reduces slightly and forms a sauce.        
     
    
        
            6        
        
            Season again with salt and pepper if needed, crumble bacon over top, and serve with Parmigiano-Reggiano.