Bring a large pot of water to boil for pasta. Once the pasta water is at full rolling boil, season it liberally with salt and cook pasta 1 minute less than package directions.
Meanwhile, heat a large pot or skillet with a lid over medium-high heat with EVOO, 3 turns of the pan. Add garlic and swirl a minute. Add dollops of 'nduja and melt it down (or add the sausage and brown and crumble). Add vermouth or wine and stir a minute. Add tomatoes, oregano and mussels and cover. Cook 10 to 12 minutes, stirring occasionally, to open shells and combine flavors. Uncover.
Drain pasta and toss with sauce and mussels, 1 minute. Add parsley, lemon and salt to taste.