Heat the oil over medium high heat and sauté the onions and peppers until the vegetables are soft, about 5 minutes.
Add the mushrooms, season lightly with salt and red pepper flakes, and continue to cook, stirring as needed, until the mushrooms begin to brown around the edges.
Add the garlic, chili powder, cumin, oregano, coriander, bay leaves, and cook until the spices are fragrant, 1 to 2 minutes.
Stir in the canned tomatoes and bring to a simmer. Lower heat and cook for about 5 minutes, adding more water if the chili gets too thick.
Add the beans and lentils and cook until thickened, about 5 minutes longer. Stir in the zucchini and cook for 5 minutes. Adjust spices and salt to taste then remove from heat. Serve with tortilla chips, garlic toast, avocado, lime wedges, and/or plant-based sour cream/queso/shredded cheese.