Simplicity itself yet so versatile that it can be served with many dishes
We always have this on the table when we eat Raclette
Add the mustard and oil into a bowl and mix well until it's creamy.
Cut the tomatoes into 8 segments each and add to the bowl with the mustard/oil mix.
Slice the onion and add this into the bowl
Give a few good cracks of black pepper, mix the ingredients and leave covered with cling film on the work surface for about an hour so the flavours infuse