Sauté the onions in a large pan with a little water. Add garlic and mushrooms and continue to cook until they're almost soft. Add the beans and chard and cook until wilted. Add the sun-dried tomatoes, the pasta sauce, and rice. Stir to combine.
Fill the peppers until full and top with chopped cashews. Cook covered with foil for 20-25 minutes until heated through. Remove foil and brown cashews for another 5-10 minutes. Enjoy!