Remove the stems of the portobello mushrooms and set aside. Preheat over to 400 or 425 degrees. Add ¼ cup of water to a baking sheet and place mushrooms stem side down. Bake for 10 minutes and remove from heat.
While the mushrooms are baking, add the chickpeas, parsley, cilantro, red onion, Italian breadcrumbs, miso paste, nutritional yeast, and pepper to a food processor. Process until evenly mixed. Optional: add 3 tablespoons of diced red onions and pulse to combine for some nice texture.
Turn the mushrooms over and stuff the mushrooms with the filling, dividing evenly. Bake for 20 minutes.
Slice the portobello mushroom stems and white mushrooms and sauté until softened. Add the mushrooms, sage, thyme, veggie cube, miso paste, garlic, and water to a blender. Blend until smooth.
Spoon the gravy over the mushrooms and garnish with fresh parsley.