Preheat the oven to 425°F and grease a large rimmed nonstick baking sheet with cooking spray.
In a large bowl, add the ground chicken, panko, almond flour, grated zucchini, egg, shallots, garlic, salt, and pepper, then mix by hand until combined.
Roll into 27-30 meatballs and set onto half of the baking sheet (or use a cookie scoop), placing them very close to each other to fit on one half of the pan. Spray the meatballs with cooking spray.
Place the Brussels sprouts and mushrooms onto the other side of the baking sheet and toss with avocado oil and salt. Spread into an even layer on half of the baking sheet.
Bake for 25-30 minutes until everything is cooked through.
While the meatballs & veggies bake, in a large skillet over medium heat, warm the butter and broth until melted. Whisk in the garlic, sage leaves, salt and cornstarch and cook for 3-5 minutes over medium-high heat until thickened, whisking often. Turn off the heat, remove the sage leaves, and set aside 1/4-1/3 cup of the sauce for drizzling later.
Transfer the baked meatballs to the skillet of sage butter sauce and mix to coat.
Assemble the bowls – Evenly divide the wild rice, sage butter meatballs, roasted mushrooms, and Brussels sprouts. Top with parmesan cheese, chopped sage, pomegranate arils, and a drizzle of remaining sage butter sauce.