In a large soup pot over medium/low heat, add ½ cup of vegetable broth, onion, red bell pepper, and parsley. Sauté the onion until translucent.
While the onion is sautéing, dice the carrot, sweet potato, potato, and mushrooms. Add the carrot first and continue sautéing for about 5-7 min (add a little bit of water if needed). Then add the sweet potato, potato, and mushrooms.
Pour diced tomatoes, tomato paste, the rest of the vegetable broth, and the lentils into the pot. Add the garlic powder, onion powder, paprika, bay leaves, black pepper, and salt if using. Add some hot water, enough to cover all the ingredients. Stir to combine, place the lid, and bring to a simmer over medium/high heat.
Low the heat to medium/low and continue cooking the ingredients between 45 min to 1 hour, stirring occasionally and adding hot water to keep the stew with liquid all the time.
When the lentils, sweet potato, potato, and carrot are cooked and soft, the stew is done.
Serve it with some parsley, and enjoy!