Pat the chicken dry with paper towels. If starting with whole breasts, carefully slice them in half horizontally to make 4 even cutlets. If using store-bought cutlets, you can skip the slicing. Season both sides generously with salt and pepper, then place on a plate.
Measure the bread crumbs into a shallow bowl.
Crack the egg into a medium-size shallow bowl and whisk it with a fork to break it up. Add the sour cream, Dijon mustard, chives and flour. Stir together until smooth.
With a fork or tongs, dip a chicken cutlet into the bowl of wet mixture, turning to coat both sides. Lift it into the dish of bread crumbs, pressing down with the back of the fork. Turn the cutlet to the opposite side and spoon bread crumbs over the top, also pressing to allow the crumbs to adhere.
Place each breaded cutlet on a plate, then repeat with the remaining pieces. Chill the cutlets in the refrigerator for 30 minutes to help the coating set.
Heat an 8-inch cast iron or stainless steel skillet over medium-high heat, add 2 tablespoons of the oil and when it is hot place 2 of the cutlets into the skillet. Cook the cutlets for 4 minutes until golden brown, flip them over and cook for an additional 3 minutes.
Transfer the cutlets to a paper towel-lined plate. Add the remaining 2 tablespoons of oil and when it is hot, repeat the process with the additional chicken cutlets.
Transfer the cooked cutlets to a serving platter. Garnish the cutlets with chopped chives and lemon wedges and serve a small dish of sour cream along side.
Notes
Easy slicing: Cutting chicken breasts horizontally can be tricky. Partially freezing the meat first helps firm it up, making slicing easier and safer.How to slice: Place the chicken on a cutting board with one hand flat on top. With the other hand, carefully slice lengthwise, keeping the knife parallel to the board.Chill for crispiness: Refrigerating the breaded cutlets before frying isn’t essential, but it helps the coating set and creates a crisper crust.Choose the right oil: Use a high-heat oil like canola, vegetable, avocado, or grapeseed. Avoid olive oil, which isn’t ideal for frying at higher temps.