Tuna sandwiches are perfect for July, when the height of summer leaves most of us with little desire to cook, and we just want some simple food to enjoy outdoors in the sun. However, they can often end up greasy and utterly unappetizing in hot weather, as most people make the mistake of using mayonnaise.

I used to always make my sandwiches with mayonnaise as it gives them a creamy texture, but this spread is mostly made up of oil and eggs, which spoil quickly when heated up. I recently made the mistake of packing tuna melts for a picnic with friends, and in just one hour of arriving, the sandwiches were a soggy mess that smelled awful. After the horrific experience of cleaning up the rancid filling in 30-degree heat, I decided there had to be a better way to make tuna sandwiches and discovered they taste even better when you swap mayonnaise for Greek yoghurt.

Making sandwiches with Greek yoghurt might sound silly, but after trying countless sandwich recipes this summer, I can assure you they not only taste delicious but also hold up much better in hot weather.

Greek yoghurt is thick and smooth, giving tuna filling a satisfying creamy texture without needing to use mayonnaise at all.

It has a much lighter consistency and a slight acidity that makes tuna taste more savoury while also brightening the flavours of any vegetables in the sandwich.

Mayonnaise can make a sandwich feel heavy, overpowering the other ingredients and leaving each bite tasting overly rich and cloying.

I prefer using Greek yoghurt because it makes the tuna filling taste much fresher, without the richness of mayonnaise, which can quickly become funky and sour in the summer heat.

1. All you need to do is drain the tuna, then chop up the celery and red onion, which should take roughly five minutes.

2. Place the drained tuna in a bowl, and also add the celery and red onion. Season with salt, pepper and smoked paprika.

3. Pour the lemon juice into the bowl and add your Greek yoghurt on top. Mix everything together until the tuna filling has a creamy consistency.

4. Put the bread into the toaster, and once it is ready, simply assemble your sandwich by spooning the tuna filling onto the toast.

Your tuna sandwich should now be fresher, crisper and far more satisfying, which proves changing one simple ingredient can turn an everyday lunch into the perfect picnic treat.