Preheat oven to 375°. Lightly oil a 9 inch loaf pan and arrange a strip of parchment paper width-wise along the center, with just a bit hanging over the sides.
Saute the vegetables in a little water, till the onions are well softened.
In a food processor, process the chickpeas, panko breadcrumbs, soy milk, worcestershire sauce, tamari, olive oil, flax seeds, tomato paste, liquid smoke, black pepper and half of the cooked veggie mixture. Pulse, process until the mixture is half mashed and half coarsely chunky. Do not over-blend. Work in batches if needed.
Press mixture into prepared loaf pan and bake 30 minutes.
While meatloaf bakes, stir the 1/4 cup of tomato paste, 2 tablespoons of maple syrup, 2 tablespoons of apple cider vinegar, 1 tablespoon of tamari soy sauce, 1 teaspoon of paprika together in a small bowl for the glaze.
During the last 25 minutes of baking the loaf, roast alongside the brussels sprouts and parsnips in instantpot for 5 minutes, natural release.
Remove loaf from oven after 30 minutes and spoon glaze over top of loaf. Bake another 20-25 minutes. Remove from oven and allow to cool at least 10 minutes before cutting.
Serve with vegan gravy or other sides of choice.