First, blanch the green beans. Bring 2-3 cup of water to a boil in a small saucepan. Add the beans, let cook for just a minute or two until vibrant green, then strain and run under cold water. Set aside.
Preheat oven to 400. In a bowl, whisk together the ketchup, tahini, mustard, garlic, vinegar, tamari, Worcestershire sauce, and chioptle hot sauce, and then whisk in the water. Once well incorporated, stir in the shallots/onion.
Transfer the mixture to a baking dish (8×11 or similar size). Add the chickpeas and stir through. Bake, covered, 25 minutes.
Add the green beans, stir through, re-cover, and bake for another 4-5 minutes (not much longer, or the beans will turn a gray color). Remove and serve.