Preheat the oven to 200C fan.
Chop the courgette into small bite size cubes. Chop the red onion into slices. Chop the asparagus into thirds. Add them to a lined baking tray, toss in 1 tbsp of oil, 1/2 tsp of salt and 1 tbsp of balsamic vinegar and mix well. Bake them in the oven for 15 - 20 minutes until nicely roasted.
Chop the feta into cubes. Cut the puff pastry/shortcrust sheet into quarters so you have 4 rectangles. Cover the frozen peas with boiling water for 10 mins then drain and set aside.
Using a rolling pin or a clean dry glass jar, roll each rectangle so that its size increases by approx 2 cm each side.
Remove the roasted veg from the oven, reduce the oven temperature to 180 C Fan, mix well and leave it aside to cool before adding to the pastry.
Drain the peas, chop the basil and mix them both through the cooked veg.
Mix together the pesto and the tomato puree and cover each of pastry pieces, approx 1 Tbsp of the mixture, leaving 1 cm from the edge free from sauce.
Spoon approx ¼ of the spring veg mixture into the middle of each of the 4 quarters of the pastry. Add a quarter of the vegan feta to each.
Fold and seal into a hot pocket/parcel shape and turn over so seam side down- like mini wellingtons, taking care not to tear the pastry. Transfer carefully to a parchment lined baking tray.
Using a pastry brush, brush each parcel with oat milk for short crust pastry or oil for puff pastry, this will simply help them brown.
Bake in the oven for 20- 25 minutes until the parcels are an even golden colour. Enjoy!