Jeon—crispy, savory pancakes—are a popular snack in Korea. Pajeon (“pa” means “scallions” in Korean) is one of the most popular varieties.
For the dipping sauce: In small bowl, whisk together all dipping sauce ingredients.
For the pancake: Line large plate with double layer of paper towels. Place scallions on cutting board. Use chef’s knife to cut dark-green scallion tops from white and light-green bottoms. Cut white and light-green parts in half lengthwise (the long way; skip this step if your scallions are skinny). Cut all scallion parts crosswise (the short way) into 2-inch pieces.
In medium bowl, whisk together flour, potato starch, baking powder, baking soda, pepper, salt, and ½ teaspoon sugar. Add ice water and garlic and whisk until smooth. Use rubber spatula to gently stir in scallions until mixture is evenly combined (do not overmix).
In 10-inch nonstick skillet, heat 2 tablespoons oil over medium-high heat until just beginning to smoke, about 3 minutes. (You should start to see wisps of smoke coming up from oil; you may need to get eye level with skillet to see this. Turn on your stove’s vent hood, if you have one.) Scrape all of batter into center of skillet. Spread into even circle covering bottom of skillet. Shake skillet to distribute oil under pancake.
Cook until bubbles at center of pancake burst and leave holes in surface and underside is golden brown, 3 to 5 minutes. (Oil should be gently sizzling as pancake cooks; if oil begins to smoke, reduce heat to medium.)
Use spatula to flip pancake and press firmly into skillet to flatten. Drizzle remaining 1 tablespoon oil around edges of skillet. Continue to cook, pressing pancake occasionally to flatten, until second side is spotty golden brown, 2 to 4 minutes. Turn off heat.
Instead of scallions, try using 1 cup of chopped baby greens (such as kale, arugula, or spinach), 1 cup of sliced mushrooms, or ½ cup of chopped kimchi.
Jeon are savory, crispy Korean pancakes that can be made with a wide array of ingredients. Pajeon (“pa” means “scallions” in Korean) is one of the most popular varieties, featuring a crispy, browned exterior and a soft, chewy interior that’s packed with oniony scallions. In Korea, pajeon is a particularly popular snack on rainy days: Some say that the sputter and sizzle of the pajeon batter cooking in oil sounds like the rhythmic tapping of rainfall.