Cut your potatoes into your preffered sized peices – I like to halve new potatoes. I tend to keep the skin on, but you can also peel depending on preference.
Add your potatoes to boiling water for 15-20 minutes, if you stick a knife in you'll be able to tell when they're soft. Add your frozen petit pois 2 minutes before the end.
In a large bowl mix your chopped fresh mint, mince garlic, raw red onion, mayonnaise and yoghurt.
Leave your potatoes to cool completely (you can soak in cold water to speed this up), and drain them until dry before adding to your bowl. Stir all together and add salt and pepper to taste.
At this point I add in a little extra yoghurt or mayonnaise so i have a nice creamy finish.