Cut your baby potatoes in half and place in a large pot. Cover with water and place on the stove. High heat until the water boils, then reduce heat to medium for 5 mins. Check to see the potatoes are tender by poking with a knife.
Drain the potatoes when done and rinse with cold water. You will need to ensure the potatoes are completely cold before adding to the other ingredients.
Dice your red onion and spring onions and set aside.
Combine the Sheese, vegan mayo and seeded mustard and mix til combined.
Take the cold potatoes, red onion and place in your salad bowl. Cover with the mayo mixture and mix thoroughly.
Sprinkle with the spring onions.