Step 1: Rinse the shishito peppers thoroughly under cold water. Pat them completely dry with paper towels. Ensure they are as dry as possible to achieve optimal blistering and prevent oil splattering.
Step 2: Heat a large (10-12 inch) cast-iron skillet or other heavy-bottomed pan over medium-high heat for 2-3 minutes. Add the oil to the hot pan and swirl to coat. The oil should be shimmering and almost smoking.
Step 3: Add the dry shishito peppers to the hot pan in a single layer. Do not overcrowd the pan; if necessary, cook in two batches to ensure proper blistering instead of steaming.
Step 4: Cook the peppers undisturbed for 2-3 minutes until they start to blister and char deeply on one side. You’ll see dark, browned spots appearing.
Step 5: Using tongs, toss or flip the peppers to cook on other sides. Continue cooking for another 2-3 minutes, or until all sides are blistered, softened, and slightly wrinkled, but still retaining some crispness.
Step 6: Immediately remove the blistered peppers from the heat and transfer them to a serving plate or bowl.
Step 7: Squeeze fresh lemon juice over the hot peppers. The citrus brightens the flavor and adds a refreshing tang.
Step 8: Generously sprinkle the peppers with flaky sea salt. The salt will adhere best to the warm, oily surface.
Step 9: Serve the blistered shishito peppers immediately as an appetizer or a light snack. They are best enjoyed hot and fresh.