What can I serve with this? I served with mashed potatoes and some green peas. This would be really good with brown rice or some baby new potatoes. Green beans or tenderstem broccoli would work well too.

Instead of cod: use haddock, hake or pollock. Any chunky white fish works. You could also use salmon or trout but I prefer white fish best here.

Variations: add a little fried chorizo to the tomatoes - fry the chorizo first until crispy and then make the tomato sauce and scatter the chorizo over the cod. Would also be really nice with some strips of roasted red pepper - just use the jarred ones. Parsley, basil and chives all work really well in the butter sauce, so use what you have to hand, or your favourite. Butter, garlic and herbs, you can’t go too far wrong. I always add the herbs off the heat as I like them to keep a bit of their freshness.

Make this recipe even easier: Serve with a pouch of microwave rice and then you only have to worry about the cod. Or just with a big handful of rocket and a drizzle of balsamic. You can also make the tomato sauce without the onions, and just make a very simple garlic and tomato sauce with plenty of olive oil. This will save a bit of time and you will get it in the oven that little bit faster.

A note on butter: It may seem unnecessary to add butter to the tomato sauce and the drizzle of garlic butter, but it adds so much richness, texture and flavour to the dish. It emulsifies into the tomato sauce which makes it smooth and balanced. When the butter is divided up amongst two people, it’s really not much butter, and it’s so good. If you want to reduce the amount of butter - I get it! Leave it out of the tomato sauce and just stick with the garlic butter drizzle as it really makes the dish sing.

How to get your children to eat it too: my girls love this (minus the garlic butter) and I always serve it with mash to mop up the sauce.

Make it spicy: you could add some chopped red chilli, chilli flakes or even a dollop of spicy harissa to the tomato sauce if you want it to have a bit of a kick.

If you want to double the recipe: very simple, just double all the ingredients and go on as normal. You could keep the garlic butter quantities the same - that should be enough to drizzle over a dish, whether it's for 2 or 4 people.

What to do with leftovers: Any leftovers can be stored in an airtight container for a few days in the fridge. But if you only have leftover sauce and leftover garlic butter, you could make a delicious bowl of pasta. Toss the freshly cooked pasta through the leftover tomato sauce and then top with a drizzle of garlic butter.