Cut each bell pepper in half lengthwise (from stem to bottom.) Remove the stem and seeds.
Heat oil on medium heat. Saute onions until translucent. Add garlic and saute for an additional minute.
Add diced tomatoes, 1 cup of vegetable broth, tomato sauce, and seasonings (oregano, cumin, salt, and pepper.) Simmer for 5 minutes on low heat.
In a bowl, mix together the rice, vegan beef, and parsley. Mix in 1 cup of the sauce.
Stuff each pepper with the beef and rice mixture.
Place the peppers, stuffing side up, into a 9x13 baking dish. Add the remaining ½ cup of vegetable broth to the bottom of the dish. Spoon the remaining sauce over the peppers. Cover the dish with foil.
Bake for 40 minutes. Remove the foil and bake for an additional 15 minutes, or until the filling is 160°F.