Preheat oven to 400°F. Line a baking sheet with parchment paper.
Heat olive oil in a skillet over medium heat and add butter. When butter starts to foam, add garlic and swirl; add breadcrumbs, combine with the garlic then toast to golden. Let cool. Add parsley to breadcrumbs.
Place ground chicken in a mixing bowl and add cooled, garlicky breadcrumbs, eggs, cheese, a fat drizzle of olive oil, salt and pepper. Use a scoop to roll 20-24 balls.
Place balls on parchment-lined baking sheet and roast to golden and cooked through, 20-22 minutes. Serve with marinara sauce alongside.