Serves: 12 esfihas
First make the dough. Tip the flour and salt into the bowl of a freestanding mixer with a dough hook fitted. Combine the water, yeast and sugar in a jug and stir until the sugar has dissolved. Set the motor running on a low speed and gradually pour the mixture into the flour. Knead for 3 minutes then turn the speed up a setting and knead for a further 6 minutes. Once the dough is smooth and elastic, gradually add the soft butter and knead until incorporated. Transfer the dough to a lightly oiled bowl and dust the top with flour. Cover with a clean tea towel or a sheet of clingfilm and leave to rise in a warm place for 1 ½ hours until doubled in size.
Remove the tea towel and punch the dough once to knock the air out. Divide the dough into 12 balls then cover with a clean tea towel and set aside for 1 hour until doubled in size. While the dough is rising, make the sauce. Heat a little olive oil in a heavy-based pan, add the shallots and garlic and fry for 5 minutes until soft. Add the chilli flakes, tomatoes, tomato purée, sugar and olives and bring to a simmer. Cook gently for 25 to 30 minutes until thickened. Stir through the basil and season to taste. Set aside to cool.
Preheat the oven to 200°C. Dust the work surface with semolina flour and roll the dough out into small rounds, about 1 centimetre thick. Using your fingertips, press and turn the centre of each dough ball to create a rim around the edge (it should resemble a small, deep sided pizza).
Lay on baking sheets and leave plenty of space between each one as they will rise during cooking. Spoon a little sauce into the centre of each disc of dough then top each with and anchovy and a little feta cheese. Mix together the egg yolks and oil and brush over the edges of the dough.
Bake for 10 to 12 minutes until risen and golden. Remove from the oven and leave to rest for a couple of minutes. Just before the esfihas are ready, preheat a griddle pan over a high heat. Rub the tuna steaks with a little oil and season with salt and pepper. Griddle the tuna for 30 seconds on each side (or slightly longer if the steaks are thick) then set aside to rest. Slice the tuna thinly, arrange over the top of the esfihas and serve.