Tuna melts are arguably my favourite sandwich, all melty, pickley and delicious. A general gripe I have is when there isn’t enough mayonnaise in the tuna mixture and it ends up tasting canned and metallic – so use lots and don’t be shy.

But tuna sambal is so packed with flavour already, you run very little risk of metallic canned fish flavours spoiling your toastie. The cheese does a marvellous job of tempering the spice from the sambal, leaving you with a far gentler meal.

Rosheen Kaul. Photograph: Murdoch Books/Armelle Habib

First make the sambal, which is a mixture inspired by a dish from Manado in Indonesia that I have fond memories of – called cakalang rica-rica. The original dish is a fiery, dry stir-fry of smoked skipjack tuna; hugely flavourful and eye-wateringly spicy. You don’t need to make this sambal anywhere near as hot, but if you want to you can, by adding a couple of fistfuls of bird’s-eye or Thai chillies.

You’ll need a cast-iron skillet or a sandwich press for the toastie. Remember, mayonnaise is the gold standard for a perfectly golden toasted sandwich exterior. It forms an iron-clad surface that keeps your sandwich nice and crisp.

Rosheen Kaul’s tuna sambal – recipe

Makes 2 cups (500ml)

8 small Asian shallots or 4 French shallots
10 long red chillies
4 red bird’s-eye chillies
4 cloves garlic
1 tomato
2 lemongrass stalks
, tender white part only of one, the other thinly sliced
½ tsp turmeric powder
1½ tbsp neutral oil
, for frying
3 makrut lime leaves, thinly sliced
½ red onion, diced
500g good-quality tinned tuna in oil (or mackerel or sardines), drained
1 tsp fi­sh sauce
1 tsp sugar
1 tsp salt
Juice of 1 lime
1 tsp crispy shallots
(store-bought)

Place the shallots, chillies, garlic, tomato, white part of one lemongrass stalk and turmeric powder in a food processor or mortar and pestle and blend to a smooth paste.

Heat the oil to smoking point in a medium frying pan, then saute the lime leaves and sliced lemongrass over high heat until fragrant.

Add the onion and continue stir-frying until softened slightly, then add a couple of tablespoons of the sambal. Stir-fry for one to two minutes, then add the tuna.

Continue frying over medium-high heat until any liquid evaporates and the tuna begins to dry out somewhat in the pan. Break up any larger pieces of tuna as you continue to fry, then add the fi­sh sauce and sugar. Taste at this point, add a little more sambal if you wish, and skip the salt if the tuna is already salty.

If you add more sambal or seasoning, fry for a further few minutes until it’s lovely and dry. Once you’re happy, add the lime juice and fold through the crispy shallots to serve.

The tuna sambal will keep for up to five days in the fridge in an airtight container. Reheat it well before you eat it.

Tuna sambal melt – recipe

Serves 1

½ cup (125ml) tuna sambal (recipe above)
2 tbsp mayonnaise
½ tsp chopped pickled capers or jalapeños
½ tsp finely minced French or Asian shallots
1 tbsp finely chopped parsley and dill
2 slices bread
4 slices American or cheddar cheese
­Flaky salt
, to taste

Combine the tuna sambal, half the mayonnaise, chopped pickled capers or jalapeños, shallot and herbs in a small bowl. Taste and adjust the seasoning as you like. Add sliced fresh chillies too, if you’re feeling spicy.

Spread the remaining mayonnaise on all surfaces of the bread, then assemble the sandwich, beginning with two slices of cheese on the base, then the sambal tuna filling, followed by the remaining two slices of cheese. Top with the second slice of mayonnaised bread.

Heat a cast-iron skillet over medium heat, or use a sandwich press. Gently place the sandwich on the hot surface of the pan, then press down and cook until it has a crisp, golden surface and melty cheese inside. If you’re using a skillet, cook for about four minutes either side, carefully fl­ipping in between, and make sure you keep pressing down on the sandwich as it cooks.

Transfer to a chopping board and sprinkle with a little ­flaky salt if you have it. Cut in half and eat immediately.

  • This is an edited extract from Secret Sauce by Rosheen Kaul, photography by Armelle Habib (Murdoch Books; $39.99)