If you need to make mashed potatoes for this recipe, make them first and let them cool before continuing.
Peel and shred 2 pounds of raw potatoes over a clean kitchen towel, cheesecloth, or muslin cloth. Squeeze out as much liquid as you can, then mix into 2 cups of mashed potatoes to avoid too much oxidation.
(Optionally, strain out the water into a bowl and let it sit for 20-30 minutes. You can then pour off the liquid and mix the separated starch left behind into the potatoes.)
Stir in 1 ¼ cups all-purpose flour, 1 teaspoon salt, and 1 teaspoon baking soda and mix until well combined. Now add ¾ cup buttermilk and mix until fully incorporated and it forms a thick batter.
Heat a cast iron or nonstick skillet over medium-low to medium heat. Melt some butter and then scoop in some of the batter (roughly a ¼ cup), forming round patties about a ½” thick. Cook on one side for 4-5 minutes until golden brown on the bottom. Flip and cook another 3-4 minutes on the opposite side.
Keep batches warm in a 200°F oven and serve hot with some good Irish butter on top.
1) Buttermilk – If you do not have buttermilk, add a teaspoon of vinegar or lemon juice to a measuring glass and add whatever milk you do have until it comes to ¾ cup. Let stand for about 5 minutes and use as a buttermilk replacement.2) Cooking – Do not try cooking faster at a higher temperature. The biggest trick to getting boxty cooked properly is to have the outside nice and crispy while the inside gets fully cooked at the same time. Like regular pancakes, you may want to make a test one first to see if the temperate is right. If the bottom is getting too dark before 4-5 minutes of cooking on the first side, turn down the temperature.