Prepare the chili and mashed potatoes the night before. This will give you time to refrigerate them overnight, which will make them easier to work with.
To make mashed potatoes, add potatoes to a large pot filled with water. Boil potatoes until fork-tender (about 20-25 minutes, depending on the size of your potatoes). Drain water from potatoes. Add in butter and milk. Mash potatoes, milk and butter with a potato masher. You want the mash to be quite thick as it will be easier to shape and fry later. Let mashed potatoes cool before storing in the fridge.
On the day of serving the potatoes, add whisked eggs to one medium bowl. Add 1 cup of panko crumbs to a different medium bowl. Scoop out 1 ½ tbsp of cold mashed potatoes. Place onto a piece of plastic wrap big enough to wrap around the potato ball. Press mashed potatoes into a thin pancake. Scoop slightly less than 1 tbsp of chili on top, trying to avoid using the thinner liquid from the chili. Add another 1 tbsp thin layer of mashed potatoes on top. Using the plastic wrap, seal the chili within the mashed potato and form a tight ball. If desired, you can also shape them to resemble footballs. Release ball from plastic wrap and set aside. Repeat with remaining mashed potatoes and filling.
Roll potato ball gently in whisked egg, letting any loose egg drippings drip off before placing the ball into the panko crumbs bowl. Then roll in panko crumbs. I find it is easier to place ball into bowl with crumbs and then scoop and pour more crumbs over the ball. Set aside and repeat with remaining potato balls. When you run low on the panko crumbs, add another 1 cup. You don’t want to add all the crumbs at once because the crumbs don’t stick as well when they get moist.
Add enough oil into a large pot being used for frying to cover potato balls. Bring oil to medium heat. Add a few potato balls at a time and cook until golden, occasionally flipping balls so that they are evenly cooked.
Serve potato balls with Stubb’s BBQ sauce.
*These potato balls cook best while still firm and cold. If it’s a hot day or you took a long time to make your potato balls, keep balls chilling in fridge until ready to fry.
*Be careful not to fry them at too high heat. The strong bubbling of the oil can cause the potato balls to break open.