Preheat a grill or grill pan.
Place a small sauté pan over medium high heat and toast each of the seeds separately for 1 to 2 minutes and remove from pan to a mixing bowl to cool.
Using a mortar and pestle or a food processor grind the spices into a powder being sure to break up any large pieces of the seeds. Pass the spice mix through a small sifter into a mixing bowl and mix well, set aside.
On a clean work surface lay out several even layers of plastic wrap approximately 1 foot wide and place one chicken breast over the plastic. Cover the chicken with another piece of layered plastic and lightly pound the chicken breast with a meat mallet or meat tenderizer until the chicken breast is thinned out to about a ½ inch thickness, being careful not to rip or tear the chicken breast. Repeat with the second chicken breast.
Lightly brush the grill with a little vegetable oil. Season each side of the chicken generously with the spice mix and reserve any remaining spice mix for a later use in an airtight container.
Place the chicken breasts on the grill and cook for 3 to 4 minutes on each side or until an instant read thermometer inserted into the chicken reads 165 degrees F.
While the chicken is cooking mix the lemon juice, garlic, cucumber and yogurt in a small mixing bowl until well incorporated.
Remove the chicken from the grill to a plate and let rest for 2 to 3 minutes. Arrange the greens on a large serving platter. Place the chicken breasts atop the greens and drizzle the sauce over and around the chicken. Garnish the chicken with cilantro leaves and serve.
Source: Biggest Loser