1. Cut the mushrooms into small pieces and finely cut the garlic and leave aside.
2. In a saucepan, add a tsp of oil and place on medium heat, once the oil is hot, add the garlic and cook for a few minutes.
3. Take the pastry out of the fridge.
4. Add the mushrooms, followed by lemon juice, oregano, a pinch of salt, and a pinch of pepper. Cook this for 6-8 minutes on medium heat. Add the spinach and cook this for another 2 minutes or until they are slightly wilted.
5. Preheat the oven to 180 degrees.
6. Roll the pastry out and cut it into a large square. Fold about 1cm of the edges over to create the puffed border. Transfer this to an ovenproof dish with greaseproof paper (or make sure it's well oiled).
7. Spread the pesto onto the pastry, followed by the mushroom-spinach mix.
8. Add the mozzarella pieces on top and cook this in the oven for 15-20 minutes until the pastry is golden brown.
9. Serve with salad.
10. Enjoy!