Maincrop potatos while still small

Hi, my main crop potatos are still small and obviously need another month or two to be good for roasting or baking or whatever. However can I harvest one or two plants and use them like new potatos? It's just none of my earlies ever came up and fancy making wedges for tea

I'm just back from a lunchtime trip to my allotment and I had lifted a bucket full of earlies (epicure) but I also pulled up one of my maincrop plants (pink fir apple). The PFA are still quite small but I'm going to use them as new potatoes and I'm sure they'll be delicious! I'll leave the rest to get bigger.