Preheat the oven to 200C/400F/Gas Mark 6.
In a large bowl, add the flour, coconut oil, dairy-free butter and salt. Using your fingertips, rub the oil and butter together with the flour until it forms a breadcrumb-like consistency. Add the water and bring the dough together with your hands to form a ball. Place in the fridge.
Place a frying pan over a medium-high heat and add 1 tbsp olive oil. Once hot, add the chopped leeks. Cook for five minutes until softened, stirring frequently. Once softened, add the pesto and mix in thoroughly. Set to one side.
Use a vegetable peeler to carefully slice the courgette and butternut squash into thin strips.
Grease an 8” loose-bottomed tin or a tart tin. Dust a rolling pin and surface with a little extra flour. Carefully roll out the pastry and cover the bottom and sides of the tin with an even layer.
Scoop the leek mixture onto the pastry and spread evenly.
To create the roses, roll a strip of courgette tightly. Take another strip and roll it tightly around the first one. You will need two or three strips to create one rose, depending on the length of the pieces. Repeat until you have enough courgette roses for an outer ring (see pictures). Then repeat with the strips of butternut squash until you have enough roses and the tart is filled. Brush the top of the roses lightly with a little oil.
Place the tart into the oven
Cook for one hour or until the pastry of the tart has cooked thoroughly.
Remove from the oven, serve and enjoy!