To make the pastry, pulse the flour and butter in a food processor until it’s like breadcrumbs.
Add the egg yolks and water and blend until it comes together as a dough. Wrap and chill in the fridge for 15 minutes.
Preheat the oven to 160C (140C fan, 320F). Cut the dough into four and roll out each piece large enough to line your 12cm springform tins.
Place the pastry in the tins. If the pastry breaks, just patch it up as you go. As long as there are no holes, you're fine. Line with greaseproof and fill with baking beans.
Bake for 15 mins then take out of the oven and remove the paper and beans. Return to the oven for a further 10-15 minutes until just turning golden and totally dry at the bottom. Trim off any excess and allow to cool.
To make the tomato sauce
Warm the olive oil in a large non-stick pan over a medium heat.
Add the onion, garlic and pepper and fry gently for 10 minutes until soft.
Add the oregano, tomatoes, salt and pepper and simmer for 5 minutes until slightly thickened. Allow to cool.
To make the white sauce
Out the butter, flour and milk in a non-stick pan and place over a medium-low heat.
Whisk continually until the sauce is completely smooth and slightly thickened.
Take off the heat, add the cheese and stir through until combined.
Soak the lasagne sheets in a little boiling water for 3 minutes.
Pick a cookie cutter slightly smaller than the tin and use to cut rounds out of each of the sheets. lasagne sheet rounds.
Now it's time to fill your pies. Starting a scant layer of tomato sauce, followed by a lasagne round. Repeat until your final lasagne round almost reaches the top. Top with the white sauce.
Bake for 30-35 minutes until browned and bubbling on top. Enjoy hot or cold.