I quite like burgers, but prefer not to eat my dinner between two thick chunks of bread, so here I have served the burger on rösti,
much more sophisticated! For the burgers, put 50g sliced pancetta into the freezer for a couple of hours, then cut into 3cm chunks
and mince up in a food processor. Freezing the pancetta makes it very easy to mince. Mix this into 200g minced beef, together with
finely diced shallots, 80g of crumbled feta cheese and plenty of freshly ground black pepper, form into two oval patties about 2 cm thick,
and chill in the refrigerator for an hour or so. Meanwhile, parboil potatoes for about 7-8 minutes, cool and grate into a bowl.
Leaving the skins on adds to the flavour. Season well with salt and pepper, then heat some butter in a flying pan, tip in the grated potatoes,
shape into two oval patties, and sauté until cooked and crisp on each side. While the rösti are cooking, heat a ridged pan until smoking hot,
and fry the burgers on each side until nicely browned, then finish off in a 180°C oven for 10 minutes, to ensure they are fully cooked.
Serve the burger on a rösti, topped with guacamole, made by mashing together avocado with finely chopped tomato, spring onion, parsley,
a deseeded red chilli and the juice from half a lime. A simple salad on the side would be good.