2In an oven proof dish, mix the flour, 100g yoghurt, garlic powder and salt into a dough. Add a splash more yoghurt if it feels dry.
3Press the dough evenly into the dish with the back of a spoon.
4Bake the base on its own.
5While it bakes, dice the onion and tomato, slice the gherkins, and mix the remaining 20g yoghurt with the tomato sauce and mustard for the burger sauce.
6Spread the tomato paste over the base.
7Scatter over the cheese, beef and red onion.
8Bake until the cheese is bubbly.
9Cool a few minutes, then top with tomato and gherkins and drizzle over the burger sauce.