Preheat oven to 425° F. Spray potatoes with cooking spray; season with salt and pepper. Transfer potatoes to a baking sheet and roast 12 minutes, until soft to the touch.

Meanwhile, salt and pepper both sides of chicken. Spray a large nonstick skillet with cooking spray and set over high heat. Add chicken to hot pan and sear 1 minute per side, until golden brown. Add leek, carrots, mushrooms, garlic and herbs; cook 1 minute to sear vegetables. Add wine and simmer 1 minute, until liquid reduces to 1/4 cup. Add broth and simmer 5 minutes. Add Swiss chard to one side of pan and simmer 1 minute, until chicken is cooked through and greens are wilted.

To serve, place chard in the bottom of 4 shallow bowls. Slice chicken crosswise into 5 pieces each and arrange atop chard. Arrange potatoes and remaining vegetables around chicken and ladle remaining broth over the top