First, preheat your oven to 170C (150C fan). Line a large baking tray tray with baking (non-stick greaseproof) paper.
To make the filling, first wilt the spinach. You can do this by piercing the plastic packaging and microwaving for 3-4 minutes, or by boiling quickly. Transfer your spinach to a colander and leave for 5 minutes to drain well.
Slice your spring onions small and add them to a large bowl. Then add your finely chopped mint, salt, pepper and roughly crumbled feta. Squeeze (and discard) any remaining water from your spinach and add this in along with your two eggs. Mix until it’s all evenly distributed.
Open your packet of feta and lay out flat. It should be a rectangle – but we need two long, thin rectangles to make the shapes. Cut through all the sheets down the piled-up pastry’s length, right in the middle.
Take one long rectangle at a time, and brush each liberally with oil before folding. Spoon a tablespoon of your cheesy spinach mix on to the bottom end of your sheet. Take one of the corners of the sheet and fold it over the filling to the other side, making a pointed, triangle-shaped end. Take the new pointed end and fold it over the (now covered) filling. Keep folding in a triangle shape all the way up until there’s no pastry left.
Repeat for all the spanakopita and space evenly on your baking tray. Bake for 20-30 minutes, until golden brown on both the top and bottom. Don’t worry if a little eggy filling oozes out. Serve hot or cold with a Greek yoghurt dip.
Soggy bottoms are your biggest risk in Spanakopita. Don't be tempted to remove them from the oven early or turn up the oven temperature - make sure they're done by lifting them up and making sure the bottom is golden.