Make the panade. In a large mixing bowl, stir together the panko and milk. Let sit 5–10 minutes until softened.

Mix the meatballs. Add the ground turkey, garlic, eggs, Parmesan, onion, Worcestershire, thyme, rosemary, sage, salt and pepper. Mix gently by hand until just combined — don’t overmix.

Chill (optional). Cover and refrigerate the mixture for 30–60 minutes to make shaping easier.

Form the meatballs. Scoop and roll into 2-tablespoon balls (about 24 total). Place on a tray or plate.

Brown the meatballs. Heat 2 tablespoons of oil in a large deep skillet or Dutch oven over medium heat. Working in batches, sear the meatballs for about 3–4 minutes per side, turning until golden all over. (They don’t need to be fully cooked yet.) Transfer to a plate while you make the gravy.

Make the gravy. In the same pan, melt the butter over medium heat (wipe out any burnt bits if needed but keep the browned bits for flavor). Whisk in the flour and cook for 2 minutes until golden. Gradually whisk in the stock until smooth. Add thyme sprigs, salt, pepper, and Worcestershire. Bring to a gentle simmer and cook for 5 minutes, stirring often, until slightly thickened.

Simmer the meatballs in the gravy. Nestle the browned meatballs (and any juices) into the gravy in a single layer. Reduce heat to medium-low, cover, and simmer for 5-10 minutes, or until the meatballs are cooked through to 165°F inside and the gravy has thickened to your liking. Discard thyme sprigs.

Garnish and serve. If desired, fry a few sage leaves in a bit of butter or oil until crisp and use as garnish. Serve the meatballs hot over mashed potatoes, buttered noodles, or rice — spooning plenty of that rich gravy on top.