I love oily fish such as sardines, mackerel, anchovies and herring. One of my favourite quick lunches is sardines on toast, which is exactly as you would imagine: open a can of sardines (I like French, Spanish and Japanese brands), put the fish on well-buttered, good-quality toast, then pour the juices from the can over the top before eating. It's messy, but so delicious. Here are two recipes that take a little time to prepare (because you need to fillet the fish) but are a bit more elegant.

Raw sardines cured with salt, lemon zest and extra-virgin olive oil with pickled red onion (pictured)

If you can't find fresh sardines, buy other varieties of small (10cm-12cm long), oily fish such as mackerel. Buy the fish the same day you're going to fillet them, and keep them on ice or in the fridge until you're ready to use them. Filleting small fish is much easier to do than it is to describe; once you get the hang of it, each one will take less than 30 seconds.

30 fresh sardines (or other oily fish), about 10cm-12cm long, scaled and gutted

Fine sea salt, as needed

1-2 shallots, thinly sliced

2 garlic cloves, thinly sliced

The finely grated zest of one lemon

About 90ml extra-virgin olive oil

For the pickled red onion:

1 or 2 red onions, to yield 225 grams sliced

2 garlic cloves, thinly sliced

6 black peppercorns

1 bay leaf, torn into pieces

1-2 dried red chillies

120ml rice vinegar or cider vinegar

½ tsp fine sea salt

10-15 grams granulated sugar

To serve:

Good-quality bread

Extra-virgin olive oil

Rough-flaked sea salt, for sprinkling

Lemon wedges

Rinse the fish under cold, running water, then put them in a colander. Some types of fish have scutes - a short row of tiny, hard scales towards the tail end of the lateral line. To remove these, insert the tip of a knife just under the row of scutes at the tail end and cut them away, taking care not to cut deeply into the flesh.

Position the fish on the cutting board, with the back facing you, and the head to your right (if you're right handed). Using a paring knife or fish knife, insert the tip of the knife under the gill covering and cut straight down on the fish's "neck" until you reach the bone, but do not slice through it. When you reach the spine, turn your knife blade so it's facing toward the tail, and cut parallel to the cutting board, letting the fish spine and bones be your guide. Slice the fish all the way to the tail end, and cut away the fillet from the rest of the body. Flip the fish over and position it so the head is towards your left with the back facing you, and cut away the other fillet. Check each fillet for stray bones by running your fingertips gently over the fleshy side of the fish: the bones will pull out easily. After filleting all the fish, rinse the fillets with cold water, then drain them and pat them dry with paper towels. Weigh the fillets and multiply that amount by 0.035 - this is the amount of salt you will need. Weigh out the salt, then sprinkle it over the fish and mix well. Mix in the shallot, garlic, lemon zest and extra-virgin olive oil. Put the ingredients in a serving bowl, cover with cling-film and refrigerate for at least two hours.

Trim off the stem end from the onions, but leave the other end intact (this will give you something to hold when you're slicing the onions). Peel the onion, then cut it as thinly as possible (about 1mm thick) into rings - it's easiest if you use a mandoline. Fill a saucepan with water, bring to the boil then add the onion. Blanch for 30 seconds, then drain throughly. Spread the onion slices out to dry on paper towels. Put the vinegar, salt and sugar in a measuring cup, then stir until the salt and sugar are dissolved. Put the onion in a clean glass jar and add the vinegar mixture, along with the garlic, peppercorns, bay leaf and dried chilli. Leave at room temperature for at least two hours.

To make the grilled toast, slice the bread about 8mm thick. Lightly oil a grill pan and set it over a medium flame. When the pan is hot, grill the bread so it has slightly charred parallel lines. Turn the bread over once and toast the other side, adjusting the flame as needed. Drizzle olive oil over the bread.

Drain some of the pickled onion and put it on a serving platter or wooden board. Lay the sardines on the plate and add lemon wedges and a small bowl of rough-flaked sea salt. To eat, put some of the pickled onion on a slice of toast and top with the cured sardines. Squeeze lemon juice over the top, then sprinkle with a little salt.

Store leftover sardines and pickled onion in the fridge; the sardines keep for just a few days and the onion for about a month. The onion is also delicious with hamburgers and grilled or roasted meats.

Raw sardine or mackerel fillets with shallots, capers, chives, lime and piment d'espelette

12 fresh sardines or mackerels, about 10cm-12cm long, scaled and gutted

2 shallots, thinly sliced into rounds

2 heaped tsp capers

3 chives, cut into 2mm-wide pieces

About 30ml extra-virgin olive oil

About 15ml fresh lime juice

The finely grated zest of one lime

Fine sea salt

Piment d'espelette

Fillet the fish (and remove the scutes, if needed) as instructed in the first recipe. Rinse the fillets then drain them and dry them with paper towels. Lay the fillets on a serving plate and sprinkle lightly with salt.

Put the shallots in a small colander, rinse with cold water then drain. Dry the shallots with paper towels, then scatter them over the fish. Scatter the capers and chives on top. Drizzle with the olive oil and lime juice, then add the lime zest. Sprinkle very lightly with piment d'espelette then serve immediately. Serves four as an appetiser.

For more recipes, go to scmp.com/topics/recipes