Bring a large pot of salted water to a boil and cook the fusilli according to the package directions. Once it reaches a good bite, drain it in a colander and set it aside. I like to start this step first since pasta water takes the longest to come to a boil.
Heat the olive oil in a large skillet over medium-high heat. Add the sliced onions and peppers and cook, stirring occasionally, until they begin to soften. This usually takes about three to four minutes and fills the kitchen with a really good smell.
Stir in the sliced mushrooms and minced garlic, along with a sprinkle of salt and pepper. Continue cooking, stirring now and then, until everything softens further. This step takes about five to six more minutes and builds the base flavor of the dish.
Add the sliced sausage, marinara sauce and white wine to the skillet. Let it cook, stirring occasionally, until the sauce is hot, bubbly and starting to thicken. This step takes roughly ten minutes and is where the whole dish really comes together.
Add the drained pasta directly into the skillet and toss everything until it's well coated in sauce. Serve it right away with a sprinkle of grated Parmesan if that sounds good to me.