Place diced potatoes in a pot and cover with cold water and 1 tsp of salt. Bring to the boil and cook potatoes until a fork can easily slide in.
Drain the potatoes and lay out on some tea towels to dry and steam. Return the potatoes to the pot and mash until there are no longer any major lumps.
Add the mash to a large bowl with the cheese, pastrami, chives, ½ tsp salt, pepper and cream. Give it all a good mix until everything is incorporated.
Roll the mixture into small even logs, I managed to make about 15 from this recipe.
Place the eggs, flour and panko crumbs into three separate bowls to bread the croquettes.
Lightly dust each croquette in flour, followed by the egg wash, then the panko crumb.
Heat the oil up to 350°F ready for deep frying.
Fry 2 - 3 croquettes at a time until nice and golden brown. When they are done, drain on some paper towels and sprinkle with a little salt.