Step 1
Place a rack in upper and lower thirds of oven; preheat to 375°. Pour ¼ cup extra-virgin olive oil over a rimmed baking sheet; set aside. Mix one 6-oz. package stuffing mix, preferably turkey (about 2½ cups), and 1 cup whole milk in a large bowl and let sit 5 minutes.
Step 2
Mix 1 medium onion, grated on the large holes of a box grater, 1 large egg, 1 lb. ground turkey, ½ cup finely chopped parsley, 1 Tbsp. garlic powder, 1½ tsp. freshly ground pepper, and ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt in a large bowl until just combined. Working one at a time, scoop out about ¼-cup portions of meat mixture and roll into balls (they will be very soft). Place on prepared baking sheet and roll in oil to coat.
Step 3
Toss 3 lb. baby Yukon Gold, peewee, or new potatoes, scrubbed, halved, 1½ lb. green beans, trimmed, 2 tsp. Diamond Crystal or 1¼ tsp. Morton kosher salt, remaining ¼ cup extra-virgin olive oil, remaining 2 tsp. garlic powder, and remaining 1 tsp. freshly ground pepper in a large bowl to combine. Arrange vegetables in a single layer on another rimmed baking sheet.
Step 4
Bake meatballs on upper rack and vegetables on lower rack, rotating pans back to front and tossing vegetables halfway through, until meatballs are cooked through and lightly browned and potatoes are tender and deeply browned, 30–35 minutes for meatballs and 40–45 minutes for vegetables.
Step 5
Meanwhile, purée one 14-oz. can whole berry cranberry sauce, 1 tsp. finely grated lemon zest, 3 Tbsp. fresh lemon juice, 3 Tbsp. honey, and remaining ¼ tsp. Diamond Crystal or Morton kosher salt in a blender on medium until smooth, about 30 seconds. Set sauce aside until ready to serve.
Step 6
Arrange meatballs on top of vegetables and serve with reserved sauce alongside.