In a large skillet, add 2 tablespoons of olive oil. Then bring the heat to medium-high heat.
Add in 1 cup of finely chopped yellow onion and 2 minced garlic cloves. Stir until the onion becomes translucent.
Then add 8 oz of sliced baby Bella mushrooms and stir until they become tender (about 2-3 minutes).
Then pour in 2 cups puréed San Marzano tomatoes and 1 cup heavy whipping cream. Let the sauce simmer over low heat for about 5 minutes with stirring occasionally.
In the meantime, cook 18 oz of sausage ravioli in a pot of salted boiling water. Cook al dente.
Now remove the sauce from the heat and stir in 1 cup of grated Parmesan cheese. Then season with salt (to taste).
Lastly, stir in the cooked sausage ravioli and garnish with 3 chopped basil leaves. Serve warm.
Notes
Add-ins and Substitutes
Add other vegetables- If you prefer spinach, olives, peppers, or capers in your sauce, then you can add them or sub them for the mushrooms.
Make it meatier- Even though there's already Italian sausage in the ravioli, you can still saute some more sausage or even small meatballs to serve alongside this for an extra meaty meal.
Try another kind of ravioli- This creamy tomato-mushroom sauce is flavorful enough that it can shine up any type of ravioli, like cheese or spinach or whatever you have on hand.
Lighten it up. If you want a slightly lighter version, substitute regular or fat-free Half & Half. It has a similar viscosity, but not as heavy as the whipping cream.