Place the ground beef and ground sausage into a large stock pot over medium heat, season with salt, pepper and red pepper flakes to taste and cook until brown, then turn off heat.
Remove to a paper towel-lined plate to allow grease to drain (there will still be some grease left in the pot, depending on how much fat is in the meat. Leave about 1 tbsp of the grease in the pot to cook your veggies in, but drain the rest.)
Place onion and garlic in the crock pot and return heat to medium. Season with more salt and pepper. Cook until the onion is slightly translucent but not browned, and the mixture is fragrant.
Return the drained meat to the pot, then stir in tomato paste, crushed tomatoes, Italian seasoning and broth, and bring to a boil.
Add dry noodles and cook until noodles are tender, about 9 minutes.
Taste and adjust seasonings if needed.
Ladel soup into bowls and top with vegan cheese if desired.
