Cook the pasta according to package instructions. Drain, set aside.
Meanwhile, sauté the mushrooms, onion, and garlic over medium-low heat. Add in butter or oil (if using). Sauté until onions are translucent and mushrooms are cooked, 5-10 minutes. Reduce to the lowest heat setting to keep warm.
Meanwhile, drain and rinse the cashews very well.
In a high-speed blender, combine the rinsed cashews, nutritional yeast, vegetable broth, and about half a cup of the mushroom-onion mixture. Blend until smooth.
Pour the cashew-mushroom sauce over the remaining mushroom-onion mixture. Increase the heat to medium-low. Add the fresh herbs, paprika, and red pepper (if using).
Add the meatballs to the gravy and stir gently to coat; continue to cook on medium-low heat until the meatballs are heated through, 5-10 minutes.
Add lemon juice and adjust seasonings to taste, including salt, if using. Add half a cup more vegetable broth, if needed.
Serve over cooked pasta. Garnish with fresh parsley, rosemary, and/or vegan parmesan cheese.
Notes
* You may use white, red, or marsala wine; cooking wine, or additional broth.Any pasta works in this recipe. To make this gluten-free, use brown rice pasta. You can also serve this over mashed potatoes or rice.