Place in a pan, cover with water, season with some salt.
Bring to the boil and cook potatoes until tender.
Leave to cool to a temperature you can handle them.
Meanwhile, finely dice the gherkins, shallots, carrots and cooked meat if using.
Bring a pan of water to the boil, add the carrot cubes, cook for 30 seconds, then add the frozen peas and cook another 15 seconds. Drain immediately and place in a bowl.
Make the dressing by combining the mayonnaise, gherkin juice.and the white wine vinegar.
Season with salt and pepper, to taste
When the potatoes are cool enough to handle, slice them into bite size pieces
Mix the potatoes, gherkins, carrots, shallots, peas, meat and sauce carefully. Because the potatoes are still a little warm, they will soak up some of the sauce and will give the salad a lukewarm serving temperature. It can also be served cold
Present and garnish to your preference ( a great way to use leftovers)