French Onion Meatloaf with Melted Mozzarella Core Step-by-step instructions

Before you start

Before beginning, ensure all ingredients are at room temperature to promote even cooking. Have your onions sliced thinly and uniformly to ensure they caramelize at the same rate. Prepare your workspace by clearing enough room to mix the meat thoroughly without overcrowding the bowl.

Check that your oven is preheated to the correct temperature before you start assembling the loaf, as the meat should go into a hot oven immediately after shaping to retain its structure.

Instructions

Onion Preparation

1. 1Caramelize the Onions
   Melt the butter in a large skillet over medium heat. Add the sliced yellow onions and cook, stirring occasionally, until they are deep golden brown and soft. Remove from heat and chill in the refrigerator until completely cold before incorporating into the meat mixture.
   Look for Onions should be dark golden brown and very soft.
   Tip Do not rush the onions; low and slow heat brings out the natural sweetness.

The onions should be reduced significantly in volume, appearing as a deep, mahogany-colored jam. They should smell sweet and savory, with no traces of raw onion aroma. If they appear dry or are sticking to the pan, add a small splash of water or a touch more butter to keep them moving. Ensure they are chilled in the refrigerator before mixing them into the raw beef to keep the meat cold and safe.

Assembly of the Loaf

2. 2Assemble the Meatloaf
   In a large mixing bowl, combine the ground beef with the chilled caramelized onions. Mix gently until combined. Press half of the meat mixture into a loaf pan. Place the mozzarella cheese in the center, then top with the remaining meat, sealing the edges well to prevent the cheese from leaking.
   Look for The meat should be shaped into an even loaf with the cheese fully encased.
   Tip Sealing the edges ensures the cheese stays inside while baking.

The meatloaf should be tightly packed, with the mozzarella layer centered perfectly. When you fold the edges of the meat together, ensure there are no gaps or fissures in the beef. The final shape should be uniform, which helps the loaf cook at an even rate. If you notice any exposed cheese, patch it with a little extra raw meat to create a complete seal before transferring the loaf to the baking pan.

Baking and Glazing

3. 3Bake and Glaze
   Preheat the oven to 375°F (190°C). Brush the top of the meatloaf with the savory glaze. Bake for 50-60 minutes, or until the internal temperature reaches 160°F (71°C) when checked with a meat thermometer. Let it rest for 10 minutes before slicing to serve.
   Look for The glaze should be dark and glossy, and the meat cooked through.
   Safe temperature 160°F (71°C) internal temperature (ground meat)
   Tip Use a thermometer to ensure the meat is cooked safely without overcooking.

The meatloaf should be golden brown on the surface, with the glaze bubbling and dark. The center should be hot enough that the cheese is fully melted and ready to flow upon cutting.

Use your thermometer to confirm the 160°F (71°C) mark. The loaf should look sturdy and hold its shape as it sits on the platter, signaling that the proteins have set correctly and the juices have been redistributed during the rest.

Common mistakes

A common mistake is rushing the caramelization of the onions. If they are cooked over high heat, they will burn on the outside while remaining raw on the inside, leading to an acrid flavor.

Another error is failing to seal the edges of the meatloaf properly; this causes the cheese to escape into the pan, leaving you with a dry interior. Finally, slicing the meatloaf immediately after taking it out of the oven will cause it to crumble and lose its juices.

How to tell it’s done

The meatloaf is finished when the internal temperature, measured in the thickest part of the loaf, reaches 160°F (71°C). At this stage, the exterior glaze should be dark, sticky, and glossy, and the meat should feel firm to the touch.

It is vital to let the meatloaf rest on the counter for at least 10 minutes before slicing. This resting phase allows the internal juices to stabilize, which keeps the meat moist and ensures the molten cheese center stays contained.

• Ground meat: 160°F (71°C) in the thickest part