Roll out the dough and place in the tin with baking paper. Prick the base firmly with a fork, sprinkle with the cheese.
Arrange the vegetables across the dough so they overlap slightly, season with salt.
Bake for approx. 35 mins. on the bottom shelf of an oven preheated to 220°C. Take out of the oven, remove the baking paper, drizzle oil over the top.
Mix the cheese well with the other ingredients, then scatter over the flan.