Preheat the oven: Set your oven to 375°F (190°C). Line a sheet pan with foil and place a wire rack on top if you have one. Lightly oil or spray the rack so the loaf doesn’t stick. A loaf pan works too, but a free-form loaf on a rack cooks more evenly.

Mix the glaze: In a small bowl, whisk the ketchup, Dijon, vinegar, honey, and chili flakes. Set aside.

Prep the aromatics: Grate the onion on the small side of a box grater. Don’t discard the juices—this moisture keeps the meatloaf tender. Mince the garlic.

Combine the base: In a large bowl, add the ground beef, ground turkey, egg, Greek yogurt, oats or breadcrumbs, grated onion, garlic, Worcestershire, Dijon, smoked paprika, salt, pepper, and parsley. Use clean hands to mix until just combined. Avoid overmixing—it can make the meatloaf tough.

Shape the loaf: Transfer the mixture to the prepared rack or pan. Shape into a 9 x 4-inch loaf, smoothing the top. Press gently to eliminate air pockets, but don’t pack it too tightly.

First bake: Brush about half the glaze over the top and sides. Bake for 25 minutes.

Glaze again: Pull it out, brush with the remaining glaze, and return to the oven.

Bake to temperature: Continue baking 20–30 minutes, until the center reaches 160°F (71°C) on an instant-read thermometer.

Rest and slice: Let the meatloaf rest for 10–12 minutes. This helps the juices redistribute. Slice into 8–10 portions with a sharp knife.

Serve: Pair with roasted vegetables, mashed potatoes, or a simple salad. For extra protein, add a side of steamed edamame or a yogurt-based slaw.