Preheat oven to 350 degrees F.
In a large dutch oven, sauté onions over medium-high heat with a drizzle of olive oil. Add a bit of salt and pepper and cook, stirring every so often, for about 6-8 minutes or until translucent. Crumble in 3 Field Roast sausage links (or desired sausage) with the onions. (Reserve one link/some of the sausage to crumble on top!) Cook for about 10 minutes or until crispy around the edges, stirring every so often. Use a big splash of white vinegar to deglaze the bottom of the pot, about 2 tablespoons, and mix well.
Toss in the nutritional yeast, thyme, oregano, sage (fresh and dried), garlic powder, red pepper flakes, salt + pepper, and garlic. Mix well and cook for a few minutes. Once everything is toasted, add in the pumpkin, mustard, miso, and veggie broth concentrate. Mix well and pour in the oat milk, water, and cheese. Continue to mix and cook for a minute or two. Throw in the pasta and mix well. Place the lid tightly on top and bake for 30 minutes.
Take out of the oven, remove the lid, mix well, and add all of the topping ingredients evenly. Place back into the oven, uncovered, for 10-15 minutes, until crispy and browned and the pasta is fully cooked. (This may take longer depending on your oven.) Enjoy!