Cut mozzarella cheese into 4 equal pieces. Slice the onion thinly.

Place cabbage leaves in a microwave-safe container with 1 tbsp water. Cover loosely with plastic wrap and microwave at 600W for 3 minutes until softened. Let cool and pat dry with paper towels.

Lay a cabbage leaf flat on a cutting board. Place 2 slices of pork loin on top and season with salt and pepper. Add a piece of mozzarella cheese near the edge. Fold the sides of the cabbage and roll tightly. Secure with a toothpick. Repeat for all rolls.

Heat olive oil in a pot over medium heat. Add sliced onion and sauté until softened.

Add diced tomatoes, consomme, salt, pepper, and water to the pot. Bring to a boil, then add the cabbage rolls. Cover and simmer on low heat for 15 minutes.