Put the olive oil and butter in a large pot over low heat (or use your slow cooker on the lowest sauté setting) and add the onion. Cook the onion until it is translucent (about 5-6 minutes), and .then add the chopped celery and carrot. Cook for another 3-4 minutes, stirring the vegetables to make sure they are well coated with the butter and olive oil.

Add the Impossible Sausage, breaking it up as much as possible. Add salt and pepper, and cook for about 4-5 minutes until no pink patches remain.

Keeping the heat low, add the milk and the nutmeg and simmer gently until the milk is completely gone.

Add the wine, and continue to simmer until it has been absorbed into the Impossible Sausage pieces.

Add the diced tomatoes. Cook over very low heat (or the low setting on your slow cooker) for at least 3 or 4 hours. If the sauce begins to look dry or starts to stick, either add some water or some more diced tomatoes.

Add the minced fresh parsley and taste to see if the sauce needs a bit more salt and/or pepper.

Serve over pappardelle or tagliatelle, with some freshly grated Parmigiano-Reggiano.