Wrap the peppers in aluminum foil, and bake in the oven until tender, but not falling apart, about 15 minutes. Remove from the oven and allow to cool.
In a large skillet over medium heat, add the grapeseed oil. When the oil is hot, add the onions, mushrooms and garlic and saute until the mushrooms are golden brown. Add in the zucchini, yellow squash, wild rice, tomatoes, red and green peppers and continue to cook until the vegetables are tender. Adjust the seasoning with salt and pepper, to taste, and stir in the tomato paste. Remove from the heat and fold in the fresh arugula or spinach and the fresh herbs. Spoon the vegetable mixture into the cooled peppers. Transfer the peppers to a heat-proof serving dish and top with a little Parmesan. Bake until the peppers are heated through, about 15 minutes.
Remove from the oven and serve.
This can be served on a bed of fresh tomato sauce or on its own. Enjoy.