Preheat oven to 180C (fan forced).
Heat 1 tbsp oil and butter in an ovenproof large baking dish or pan over medium heat and sauté mushrooms till golden. After a couple of minutes, turn off the heat and add the spinach, stirring to combine. The spinach will cook using the residual heat. Set the mushroom and spinach mix aside for the filling.
Add the second tbsp of oil and butter in the same pan on a medium heat. Add the garlic and tomatoes and sauté till the tomatoes blister. Keep stirring the garlic so it doesn’t burn. Add passata and simmer for 2 minutes to bring the flavours together, then remove from heat and add basil.
To make the filling, add the cooked mushrooms and filling ingredients in a large bowl and mix well to combine using your hands. Season with salt and pepper
To assemble, lay out the lasagna sheet with the shorter end in front of you.
Place a generous handful of filling onto the lasagna sheet. Using a brush or your fingers, dab some water on the end furthest away from you, then roll up starting from the end closest to you. Finish with the seal down.
Roll them up so they are about 3 times thicker than an average cannelloni size.
Continue with remaining lasagna sheets. Then, cut them into sections (like mini rolls), approx. 3cm high.
Spoon the tomato sauce onto the base of the baking dish. Place the rolls around the base so they’re standing close together and spoon a little of the extra sauce over the top.
Bake for 20 minutes, remove from oven and scatter with mozzarella. Return to oven for 10 minutes or until the cheese is bubbly and golden.
Finish with more fresh basil leaves.
Let stand for 5 minutes before serving.