Mix together the mashed potatoes, beaten egg, grated cheese, flour, jalapeño pepper, and green onions until you have an even mixture. Set aside.
Heat the oil in the pan until shimmery or until it reaches 350°F on a deep-frying thermometer.
Carefully drop spoonfuls or use a small cookie scoop to drop small rounds of the batter into the hot oil.
Fry for 3 to 5 minutes, or until deep golden brown. Use a slotted spoon to transfer the Cheesy Jalapeño Potato Bites to a paper-towel lined plate to drain and immediately sprinkle with salt to taste.
Repeat with the remaining potato mixture in as many batches as needed.
Serve hot, or chill the leftover, fried Cheesy Jalapeño Potato Bites on a sheet pan, then freeze until solid and transfer to a resealable zipper top bag.
The mashed potatoes you start with should not be too slack. If you’re using Joël Robuchon’s ideal ratio (2 lbs. of potatoes to 1 lb. of butter), it’s quite likely your potatoes will be too creamy to hold together without an enormous amount of added flour which will make it taste gluey.
By the same token, but less so, you don’t want mashed potatoes that are solid as heck. I mean, you probably don’t want those mashed potatoes anyway, but especially for this. Go for the happy medium. If you can stack the mashed potatoes on your plate and they don’t slump but neither could they impersonate a volcanic boulder, you’re fine.
You don’t need a dedicated deep-fryer for this project. It’s helpful, but unnecessary. Just add about 2 to 3 inches of oil to a high-sided, heavy-bottomed pan. That’ll leave plenty of room for the boiling oil to expand without spilling over the sides after you add the little potato dumplings to it.
Before you commit to dropping 8 or 10 little Cheesy Jalapeño Potato Bites in the hot oil, please do a ‘test popper’. Scoop just one into the oil and watch how it behaves. If it browns up and holds together, you’re good. If it disintegrates in the oil, you need to stir a little more flour into the potato mixture. Add about 1/4 cup at first, then test another one. You are in good shape when it holds together and turns a lovely shade of brown!
You can drop the potato ‘batter’ by the spoonful, using one teaspoon to scrape a lump o’ tater from the other one into the oil. I prefer the precision of delivery and uniformity of size offered by a small cookie scoop.
I’m going to tell you this as plainly as possible: serve them hot. They’re OKAY when warm or room temperature, but they’re MAGICAL when hot.
If you have leftovers (and unless you’re feeding a family my size or larger, you likely will) you can freeze the already-fried Cheesy Jalapeño Potato Bites in a single layer on a baking sheet before transferring to a releasable zipper-top bag to keep frozen. Take out as many of the Cheesy Jalapeño Potato Bites as you would like and reheat on a foil lined pan in a 400°F oven for 10 to 15 minutes, or until hot all the way through.
Nutrionals are based on one Cheesy Jalapeño Potato Bite.