Heat a large pot over medium heat. Once hot, add the olive oil. Stir in the mushrooms and cook, stirring as infrequently as possible, for about 5 minutes, or until golden.
Add the onion and cook until transluscent, another 2-3 minutes.
1 small onion
Add the garlic and cook for another minute, then stir in the cumin, salt, pepper, paprika, pepper flakes, and cinnamon.
3 cloves garlic, 1 teaspoon cumin, 1 teaspoon sea salt, ½ teaspoon black pepper, ½ teaspoon smoked paprika, ½ teaspoon hot pepper flakes, ¼ teaspoon cinnamon
Add the tomatoes and stir. Add the water and cover, increasing the heat to bring to a boil.
400 grams (14 oz) canned diced tomatoes, 300 ml (1 ¼ cups) water
Once it's reached a rolling boil, add the beans, red lentils, and brown lentils. Cover again and reduce the heat to a simmer. Cook for about 20 minutes, or until the brown lentils are tender.
200 grams (1 cup) cooked or canned kidney beans, 100 grams (½ cup) red lentils, 100 grams (½ cup) brown lentils
Once the lentils are cooked, add the corn and turn off the heat. Taste and season if needed. Serve with avocado and pickled onions if desired.