In a mixing bowl, combine the egg yolk, orange rind and juice, the 125g yoghurt, flour and sugar. Mix well then fold in the grated cheese.
In a clean, grease-free bowl, whisk the egg whites until stiff.
Stir 1 tablespoon of the whisked egg white into the cheese mixture, then gently fold in the remaining egg white. Pour into the pastry case.
Bake until firm in the centre and lightly brown, 35 - 45 minutes. Cool on a wire tray.
For the orange sauce: Melt the marmalade in a pan, stirring to make sure it doesn’t burn. Remove from the heat and stir into the yogurt. For smaller quantities use 1 teaspoon of marmalade to 1 tablespoon of yogurt.
Make it healthier
For a healthier option, substitute St Helen’s Farm® natural goats’ yogurt for St Helen’s Farm® low fat goats’ yogurt.