Preheat your oven to 200ºC/400ºF/gas 6. Season your beautiful fish fillets with the rosemary, finely grated lemon zest (no bitter white pith, please) and pepper – you don’t need to use salt because we’re going to wrap the fish in the lovely salty smoked bacon. Lay your rashers of bacon or pancetta on a board and one by one run the flat of a knife along them to thin them and widen them out. Lay 3 rashers together, slightly overlapping, put a fish fillet on top and wrap the rashers around it.
Lightly heat a large ovenproof frying pan, add a splash of olive oil and lay your fish, prettiest side facing up, in the pan. Fry for a minute, then place the pan in your preheated oven for 10 to 12 minutes, depending on the thickness of the fish, until the bacon is crisp and golden.
While the fish is cooking, you can make your simple lemon mayonnaise. I do this by mixing quality low-fat mayonnaise with the juice of half a lemon and pepper. You want to add enough lemon juice to make the flavour slightly too zingy. This is because, when you eat it with the asparagus and the fish, it will lessen slightly in intensity. And don’t worry if the mayo looks a little thinner than usual when you’ve added the lemon juice – think of it as more delicate.
The asparagus is a great accompaniment because, like the fish, it also loves bacon. You can either boil or steam it; either way it’s light and a nice contrast to the meatiness of the fish. When cooked, toss it in the juices that come out of the fish. Simply serve the fish next to a nice pile of asparagus, drizzled with the lemon-spiked mayonnaise. And if you’re feeling very hungry, serve with some steaming-hot new potatoes.