In a small bowl, whisk together the egg and 1 tablespoon of the lemon juice until well combined.
In another small bowl, stir together the flour, garlic powder, and paprika.
Place each chicken breast between two sheets of waxed paper and pound with a meat mallet or rolling pin until flattened and even in thickness.
Pat the chicken dry with paper towels to help the coating adhere.
Dip each chicken breast into the egg mixture, then dredge thoroughly in the flour mixture, shaking off any excess flour.
Melt the butter in a large skillet over medium-high heat.
Add the coated chicken to the skillet and sear for 2 to 3 minutes per side until golden brown.
In a small bowl, dissolve the chicken bouillon in the hot water, then stir in the remaining 2 tablespoons lemon juice.
Pour the bouillon-lemon mixture into the skillet with the chicken and bring to a boil.
Cover the skillet, reduce the heat to low, and simmer for 10 to 15 minutes, or until the chicken is cooked through.
Transfer the chicken to serving plates, spoon the pan sauce over each piece, and garnish with capers and lemon slices.
