Preheat oven to 400 degrees F. In a large skillet, heat olive oil over medium heat, Add onion and cook, stirring, until soft, about 3 minutes. Add garlic, celery, and carrots and cook, stirring, until softened, another 3-5 minutes.
Stir in parsley, basil, oregano, thyme, and cumin, and cook for 1 minute. Add tomato paste and chickpeas and stir to coat.
Mix cornstarch with vegetable broth and Bragg's liquid aminos and add to chickpeas; bring to a boil. Reduce heat to simmer for about five more minutes, or until cornstarch is thickened and vegetables are tender.
Spread chickpea stew at the bottom of a 9x13 casserole dish, spread mashed potatoes on top, bake for 20 minutes, and broil for 5 minutes for the top to be golden brown (be careful not to burn)