Heat oven to 425 F with the rack in the middle position.
To make the meatballs, add bread crumbs and milk to a large bowl and soak until bread crumbs are soft, about 5 minutes.
Then add the rest of the meatball ingredients and gently mix with your hands, being careful not to overwork the meat.
Roll into ¾-inch meatballs, just slightly larger than the gnocchi.
In a small bowl, whisk together the ingredients for the harissa oil.
On a large rimmed sheet pan, toss the gnocchi and vegetables with the harissa oil, sprinkle with salt, and spread in a single layer.
Place the meatballs on top so they’re evenly spaced, and spray them with olive oil.
Roast for 27 to 30 minutes, gently stirring halfway through, until an instant-read thermometer inserted in the centre of the meatballs reaches 160 F.
Remove from the oven and heat broiler.
Broil for 3 to 5 minutes, until the meatballs are browned, the gnocchi are golden with crisp edges and the vegetables are tender and caramelized.
Meanwhile, in a small bowl, whisk together the ingredients for the harissa-honey drizzle.
Remove the pan from the oven.
Drizzle with harissa-honey dressing and top with feta, mint and parsley.