Season the chicken with salt and pepper. Add the flour to a shallow dish, and lightly coat the chicken breasts, shaking off any excess. Discard any excess flour.
Heat the olive oil in a medium skillet over medium-high heat. Add the chicken, cooking for 3 to 4 minutes per side, or until golden brown. Transfer the chicken to a plate, set aside.
Add the garlic, cooking for 2 to 3 minutes, or until fragrant. Add the stock, wine, and lemon zest, and simmer until the liquid has reduced by half. Add the lemon juice and capers.
Return the chicken breasts to the pan and coat with the sauce. Top with parsley.
Make the salad: Combine the arugula, tomatoes, and cucumber in a bowl. Toss with olive oil and lemon juice. Season with salt and pepper.