Unbelievable Provençal bake

Score a cross on each tomato, then carefully plunge them into a large pan of boiling water for 45 seconds, then drain in a colander and place in cold water. Peel away and discard the skins, then deseed the tomatoes and chop the flesh into 1cm chunks.Pick and finely chop the basil leaves, finely grate the lemon zest, then toss both with the tomatoes, a good splash of vinegar and a good pinch of sea salt.To start the sauce, peel and finely chop the onions. Melt the butter in a pan on a medium heat, add the onions and cook for 15 minutes, or until soft, stirring regularly.For the crêpes, melt the butter and let it cool a little while you pile the flour into a bowl with a pinch of salt. Make a well in the middle, whisk in the eggs, then gradually whisk in the milk and 70ml water until smooth. Stir in the melted butter, then leave to sit while you finish the sauce.Stir the flour into the onions to make a kind of roux, then gradually whisk in the milk until smooth. Stir in the mustard and a few scrapings of nutmeg, season, simmer for 15 minutes, then remove from the heat.Put a 26cm frying pan on a medium heat with a tiny knob of butter. Once melted, add just enough batter to coat the base of the pan, gently swirling to cover. Cook until lightly golden, then flip and cook on the other side.Repeat with the remaining batter, wiping out the pan with a ball of kitchen paper and adding a tiny knob of butter each time – you should end up with 6 crêpes.Meanwhile, grate and mix the cheeses, pick and roughly chop the parsley leaves, and tear up the slices of ham.Preheat the oven to 180ºC/350ºF/gas 4.Get yourself a deep ovenproof pan, 26cm in diameter. Repeat layers of crêpe, sauce, tomato (leaving any juices behind in the bowl), ham, cheese and parsley until you’ve used up all the ingredients, finishing with a layer of just sauce and cheese.Bake on the bottom shelf of the oven for 40 minutes, or until golden and bubbling, resting for 10 minutes before serving.Delicious served with a mixed garden salad with a French dressing made with walnut oil, and I also like to shave some walnuts on a box grater over the top of the salad for added crunch.