1. Place the chicken breasts between 2 sheets of plastic wrap or waxed paper; pound to 1/4-inch thickness with a rolling pin or meat mallet. On a sheet of waxed paper, combine the flour, salt and pepper. In a large shallow bowl, beat together the egg and 2 tablespoons water.
2. Dredge the chicken breasts in the flour mixture, one at a time, to coat lightly on both sides. Then, dip in the egg mixture to coat on both sides; let excess drip back into the bowl.
3. In a large skillet, heat 1 tablespoon of the butter and 1 tablespoon of the oil over medium-high heat. Add the chicken to the skillet, in batches if necessary, and cook, turning once, until browned and cooked through, about 6 minutes. Transfer to a plate; keep warm. Use the remaining oil to cook additional batches, if needed.
4. Just before the chicken is done, melt the remaining 2 tablespoons butter in a small skillet over medium heat. When the butter begins to foam, add the lemon juice; swirl to mix. Pour the lemon butter over the chicken and garnish with lemon slices.
Village Tip
A warm lemon will give up more juice than a chilled one. Before squeezing, place in a bowl of hot tap water for a few minutes, or cook in the microwave on High for 15 seconds.