1. Preheat oven to 400 degrees F.
2. Prepare pesto. Place cilantro and pumpkin seeds in the bowl of a food processor or blender. Pulse a few times until coarsely minced. Add cheese, pepper, and lemon zest and pulse again until combined. Scrape the sides of the bowl. Through the feed tube, add lemon juice and oil to the mixture while pulsing, until fully combined and smooth. The pesto will be thick.
3. Scoop pesto into a large bowl. Add tilapia filets to pesto and coat evenly.
4. Cut parchment paper or foil into four 18-inch long pieces. In the middle of each piece, place 1?2 cup rice, 1?4 of the green beans and 2 tilapia fillets. Place a lemon slice on top of each fillet. Fold the paper or foil in half, covering the fish, and crimp the edges all around to seal the packet. If using parchment paper, it may help to secure the edges using a metal paper clip.
5. Place pouches on a baking sheet and bake for 12 to 15 minutes. Open onepacket to check doneness: fish should be flaky and green beans tender. Transfer each packet to a dinner plate and serve immediately, instructing diners to be careful of the steam as they peel back the paper.
Source: Fresh Magazine March, April 2010