Place the frozen peas in a bowl and cover with freshly boiled water. Leave to one side while you prepare the herbs and onions.
Chop the chives, parsley and spring onions finely.
In a large bowl, place the drained peas, chopped herbs, tarragon, spring onions, garlic, salt and pepper. Mix everything together.
Next, gradually stir the mashed potatoes into the mixture and continue until all of the mashed potatoes are combined well.
Now, use clean hands to form a ball (approx. the size of a tennis ball). Compress the mixture by squeezing it together and you have a dense ball structure.
Place the ball on to a flat surface and roll it out to form the pancake shape. Use a rolling pin and a piece of baking paper to prevent it sticking.
Cut a round shape, roughly 10cm wide (use a bowl or a ramekin dish if you want to get a perfect round shape).
Heat a little oil in a frying pan and place the potato pancake in the pan on a low heat. Cook on each side for about 4mins until cooked through and golden. Continue until you have used all of the mixture. I made 10 pancakes from this mixture.