Prepare the panade & mix: In a small bowl, mash the whole wheat bread with skim milk to a paste. In a large bowl, combine turkey, 1/4 cup minced onion, garlic, salt, pepper, bread mixture, and egg yolk. Mix gently until just combined; form 20–24 1-inch meatballs. Tip: Wet hands and avoid overmixing for tender texture.

Brown the meatballs: Heat olive oil in a large skillet over medium heat until shimmering. Brown meatballs 2–3 minutes per side (they’ll finish cooking later). Transfer to a bowl; keep drippings in the skillet.

Build the mushroom base: Add remaining onion to the skillet; cook ~2 minutes until translucent. Add mushrooms; sauté 5–7 minutes until their liquid evaporates. Pour in broth and Worcestershire; bring to a rolling boil. In a cup, stir cornstarch with 1 Tbsp cold water to make a slurry.

Thicken & simmer: Whisk slurry into the boiling liquid; cook ~1 minute until visibly thickened. Stir in white wine. Return meatballs and any juices to the skillet. Reduce heat to low, cover, and simmer 5 minutes until meatballs are cooked through.

Finish creamy & serve: Turn off heat. Stir in Greek yogurt and parsley until smooth. Taste and adjust seasoning. Serve immediately over cooked no-yolk egg noodles. Tip: Add yogurt off heat to prevent curdling.