• Preheat oven to broil or grill settings on medium heat. Lightly spray a baking sheet / tray with cooking oil spray; set aside.

MEAT SAUCE:

• Heat the olive oil in a large pan or skillet. Sauté onions and garlic until translucent and fragrant over low-medium heat.
• Add in the ground beef and sausage; fry until browned, while breaking the meat up with a wooden spoon.
• Stir in 3/4 of the tomato puree. Add the tomato paste, bouillon powder, salt and pepper (to taste), and dried herbs. Bring to a simmer until sauce thickens. Remove from heat and allow to cool slightly (the sauce will be thicker than normal lasagne sauce to avoid wetting and ripping the tortillas).
• While cooling, prepare white sauce (optional)

WHITE SAUCE:

• Melt butter in a medium saucepan over medium-high heat. Add flour; cook, quickly stirring for 1 to 2 minutes. Remove from heat. Gradually add milk, starting with 1/4 cup, whisking constantly, until mixture is smooth. Return to a low heat and cook, stirring continuously with a wooden spoon, for about 10 minutes, or until sauce thickens and comes to a boil. (It should coat the back of a wooden spoon.) Remove from heat.

ASSEMBLE:

• Heat tortillas in microwave for one minute until soft. Place two slices of mozzarella onto the tortilla; spread about 1/4 cup of meat on each tortilla, and top with 2 more slices of mozzarella. Fold over tortilla ends, and roll up. Pour remaining tomato puree/sauce over the top (about 2 tablespoons each burrito), spoon white sauce over the tomato sauce, and top with the shredded mozzarella. Place burritos on prepared baking sheet / tray; bake burritos until cheese has melted and the tortillas are golden. Serve immediately.