Make meatballs: Mix ingredients in a large bowl to combine. Divide into 1-tbsp. portions; using wet hands, roll into balls. Chill on a baking sheet, covered with plastic wrap, until ready to use (up to 1 day). Preheat oven to 425°.
Prepare vegetables: Toss onion, garlic, and potatoes with oil and 1/2 tsp. each salt and pepper in a large roasting pan until evenly coated. Nestle meatballs around vegetables and bake until onion and potatoes are tender and meatballs are cooked through, about 30 minutes.
Meanwhile, cook pasta according to package directions, adding peas during the last minute of cooking. Drain, reserving some pasta water, and return pasta and peas to pot.
Stir wine into meatballs and vegetables and pour into pot of pasta. Add lemon zest and 3/4 cup parsley; toss to combine, adding pasta water if mixture looks dry. Season to taste with salt and pepper. Transfer to a plate; garnish with parsley.