Cut eggplant in half and rub olive oil, salt and pepper on all sides. Bake for 45 minutes.
In the meantime, in a food processor add walnuts, onion, garlic, jalapeño, tomato, cumin powder, Italian dried herbs, chili powder (if using), salt, soy sauce, water and fresh parsley and pulse until it resembles ground meat. Avoid blending it into a paste.
Heat a medium size pan over low-medium heat. Add oil and blended mixture, then cover with lid. When it starts to boil, tilt the lid open and simmer for 30 minutes. Stir occasionally.
Remove eggplant from the oven. Wait five minutes, then gently mash inside using a fork and stuff eggplant with walnut meat.
Top each piece of stuffed eggplant with two tablespoons of vegan sour cream and finish garnishing with some fresh parsley leaves. Serve hot.
Notes
*Note: Some new ovens have very high intense heat. Check periodically that the dish does not burn.