Heat the olive oil in a large pot over medium-high heat. Add the mushrooms, shallots and garlic, and season with salt and pepper. Cook for about 8-10 minutes. Add the pureed chickpeas, tomato paste, chili powder, thyme, parsley and water, stirring. Season with salt and pepper and bring to a boil. Lower the heat, partially cover, and gently simmer for 1 1/2 hours, adding more water and seasoning if necessary.