Preheat the oil in a large skillet on medium heat. Add the diced onions and leave to sweat for about 3 minutes. Stir in the garlic and leave to cook for another 30 seconds.
Add the ground beef and cook by tossing and crumbling until well browned—about 5 minutes.
Season with salt, bouillon powder, black pepper, oregano, thyme, and cayenne pepper.
Stir in the bell peppers, tomato sauce, and water. Cook for 30 minutes, stirring occasionally to prevent the sauce from burning.