Preheat your oven to 375 F
Add oil to a pan over medium heat, followed by the chopped carrot, celery, ginger, garlic, onion and the white ends of the green onions. Add a pinch of salt and cook over medium heat for five minutes, stirring often. We just want the veggies to soften slightly and become fragrant.
Mash the chickpeas in a medium or large bowl with a fork or masher. Add the cooked carrot celery mixture, egg if using, panko, soy sauce and miso paste. Use a spoon to mix and combine well. The mixture should be sticky and hold together. If it's dry, add more soy sauce 1-2 TBSP at a time. If it's too wet, add more panko 1-2 TBSP at a time.
Prepare a baking sheet with cooking spray. Using a 1/4 cup measuring cup or a large ice cream scoop to measure the mixture, form meatballs with your hands. You should get 12 small chickpea meatballs total (four per meal). If you want less, note that you can freeze cooked or uncooked meatballs for the future! Bake for 20 minutes, until the meatballs are firm - no flipping necessary. Set aside.
While the veg meatballs cook, make the rice: Rinse the grains in a mesh strainer, then add them to a pot with the water and a generous pinch of salt. Bring the pot to a boil, then cover and reduce to the lowest heat possible. Cook for 10 minutes (15-20 if doubling) then turn off the heat and let the rice steam for an additional 10 minutes. Then fluff with a fork and set aside.
Roast the green beans: In a bowl, toss the green beans with oil, garlic, salt and pepper. Pour the mixture onto a baking sheet and bake on the top rack for 17-20 minutes.
Make the glaze: In a measuring glass, mix the water/broth, mirin or rice vinegar substitute, miso paste, ginger and garlic. Pour the mixture into a skillet over medium high heat and whisk with a fork so the mirin dissolves. While the mixture comes to a low boil, mix the cornstarch with water (1 TBSP or 2 if doubling). Pour the cornstarch slurry into the miso mixture, bring up the heat so it's bubbling a little, and stir constantly until thickened - 3-5 mins. When it's thickened, turn off the heat add the honey and sriracha if using. Taste before you commit! Add more honey if you want it to be sweeter.
Transfer the cooked veg meatballs to the sauce and toss to coat them in it. I kept the heat on so that my sauce would thicken even more during this step!
Assemble: Divide the rice between 3 meal prep containers, then add the green beans and chicken meatballs. Garnish with chopped green onion (the green part).