Recipe has been scaled from original by 0.17x. Adjust cook times and pan sizes accordingly.
Drain and rinse kidney beans, white beans and lentils. Combine in a large pot and cover with water; boil over medium-high to high heat for 1 hour, or until tender.
Meanwhile, in a large saucepan over high heat, combine tomatoes and water; bring to a boil. Reduce heat to low and simmer, uncovered, for 1 hour, or until tomatoes are broken down.
Stir the tomatoes into the beans and add mushrooms, green bell pepper, red bell pepper, green beans, celery, onions and tofu. Season with salt, pepper, onion powder, garlic powder and chili powder to taste. Simmer for 2 to 3 hours, or until desired consistency is reached.
Meanwhile, put half of the chickpeas (reserving the rest for later) in a bowl and mash with the back of a fork until chunky. Stir in the Greek yogurt, mustard, onion powder, celery, and a dash of salt/pepper and mix well.
Mix in the remaining whole chickpeas.
Top the toast with the chickpea mixture and serve.