4large portabello steaks (or the largest brown mushrooms you can find)
Salt and pepper, to taste
For the crust:In a large bowl, combine the flour and salt. Mix the butter into the flour using your finger tips to make a wet sand. Add the eggs and mix with a fork until the dough is just coming together. Gradually add water, a spoonful at a time, just until the mixture holds together.Don’t overwork the dough. Shape into a large disc and cover in plastic wrap.Refrigerate the dough for at least 30 minutes, or make in advance the night before.
On a well floured work surface, roll the dough out into a ± 4mm thick circle. Roll up the dough onto your rolling pin. Unroll the dough over the 28cm tart tin. Press the dough into the bottom and sides of the tart tin. Trim off most of the excess leaving a few mm above the rim of the tart tin. Prick the base of the dough all over with a fork. Place in the fridge to rest for 15 minutes.
Preheat the oven to 200˚C. Fill the dough lined tart tin with scrunched up baking paper and baking beans or rice. Blind bake for 20 minutes. Remove the beans and baking paper and return to the oven for another 7 minutes. Set the crust aside.
For the filling: Whisk all the ingredients together and season well. Set aside.
For the vegetables: Using a mandolin or vegetable peeler, slice the courgettes into thin ribbons. Toss in a bowl with a good pinch of salt and place in a sieve to degorge. Slice the carrots and eggplants into thin ribbons. Using a very sharp knife, remove the core and slice the portabello mushrooms into thin strips. Trim all the vegetables so that the ribbons and slices are all as close as possible in size so they layer well together.
To assemble: Spread the filling evenly over the blind baked crust. Starting from the outside next to the crust, line the walls of the tart with the veg ribbons, alternating each veg, until the entire tin is filled.Brush the vegetables with a little olive oil and sprinkle over some salt and pepper. Bake at 200˚C for 35-40 minutes until the vegetables are just tender and cooked through and the tart base is crisp. Allow to rest for 10-15 minutes. Slice into wedges and serve with a fresh green salad.