While the pasta is cooking, puree all of the blue cheese sauce ingredients in a high-powered blender until smooth.
In a large pan, saute the onions and Brussels sprouts in a little white wine until the onions are translucent and the sprouts are tender, about 10 minutes. Add apples to pan at this time if using.
Add the pasta and the parsley to the pan, pour in the blue cheese sauce and cook until heated through, stirring to coat everything with the sauce.
Divide among 6 plates and sprinkle with additional parsley. Serve immediately.

8 ounces pasta, cooked according to package directions, rinsed under cold water and drained
1 pound fresh or frozen Brussels sprouts, cleaned and left whole if small, or cut in half if large
2 red onions, chopped
Freshly ground black pepper
1/4 cup chopped parsley, plus more for garnish
Optional: Chopped apples

Blue cheese sauce:

1/2 cup raw cashews
1/4 cup unhulled sesame seeds
1 (12.3 ounce) package firm silken tofu
4 cloves garlic, peeled
1/2 cup unsweetened soy, hemp or almond milk
1 tsp salt
3 tbsp lemon juice
1 tbsp white low-sodium miso
6 tbsp nutritional yeast
4 tsp apple cider vinegar
1 tsp Japanese plum vinegar
1 tsponion powder
1 tbsp Dijon
Dash of white wine