Cook one cup of quinoa according to package directions.
Dice yellow onion. Heat oil in wok on medium heat. Add onion and cook until slightly brown (approx. 2 minutes).
Add ground beef to the wok and cook thoroughly until the beef is browned (approx 10 minutes). Drain extra fat.
Add tomato soup, water, tamari, bouillon powder, onion powder and garlic powder to beef and stir to mix thoroughly. Leave on low heat while preparing the bell peppers.
Cut the pepper in half from the stem to the base and remove the stem and seeds.
When quinoa has finished cooking, add it to the beef mixture and stir to mix thoroughly.
Spoon beef mixture into pepper halves and place on large baking sheet.
Bake at 375℉ until the peppers are slightly softened (about 20 minutes).
Sprinkle with feta cheese and serve with salad if desired.