Great for a summertime light meal
This can, of course, be made with red tomatoes, but the yellow ones make an interesting change that will be a real talking point at your table!
Start by making the sauce. Rinse the tomatoes and halve or quarter, depending on the size. Place them in a small lidded saucepan with the chopped onion and a splash of water. Heat until the juice starts to run out of the tomatoes, adding a little more water if it threatens to burn. Then bring to the boil, reduce heat to very low and simmer, stirring occasionally, for an hour.
Strain the sauce through a mouli-legumes or sieve into a clean saucepan. If using a sieve, work the mixture through the mesh with a spoon, scraping off any that clings to the outside of the sieve, to get as much of the tomato flesh as possible and leave the skins and pips behind.
Cut the cheese into 8 pieces - chunks rather than thin slices.
Put the flour into one bowl, the beaten egg into another and the panko crumbs into a third. Roll one slice of cheese in the flour, then transfer it to the egg and turn to coat, then to the breadcrumbs and press them to the surface of it all round. Repeat for all the pieces, giving them a second coat if you have enough of the coatings left.