In a large mixing bowl, combine the ground chicken, pumpkin purée, breadcrumbs, egg, finely grated garlic, onion powder, salt, and pepper. Mix gently with your hands until just combined.

With damp hands, shape the mixture into 1.5-inch meatballs—aim for about 16 meatballs total. Place them on a plate.

Heat a nonstick skillet over medium heat and add olive oil. Once shimmering, carefully add the meatballs in a single layer. Cook for about 2–3 minutes on each side until golden brown.

In a small saucepan, melt the unsalted butter over medium heat. Add the finely chopped garlic and sage, stirring for about 30 seconds. Gradually pour in the heavy cream, followed by salt, pepper, and nutmeg. Simmer for 3–4 minutes.

Transfer the golden-brown meatballs into the sage cream sauce. Mix gently until fully coated, then let them simmer together for 5–7 minutes.

Serve the meatballs in a shallow bowl, drizzling extra sauce over the top and garnishing with additional sage leaves.