To prepare packets, start with four 20- to 24-inch-long pieces of parchment paper or foil. Fold in half crosswise. With the parchment or foil folded, draw half a heart shape on one side as you would if you were making a Valentine. Use scissors to cut out the heart shape. Open up the heart.
Place a chicken breast on one side of each open heart fairly close to the crease, leaving at least a 1-inch border around the edges for folding, and spread chicken with mustard.
Toss zucchini, yellow squash, shallots, tomatoes, oil, lemon juice, herbs, salt and pepper in a large bowl. Divide 1/4 of the vegetable mixture on top of each piece of chicken.
Close the packet to cover the ingredients. Starting at the top, seal the packet by folding the edges together in a series of small, tight folds. Twist the tip of the packet and tuck it underneath to help keep the packet closed.
Place the packets on a large rimmed baking sheet (packets may overlap slightly). Bake until the vegetables are tender and an instant-read thermometer inserted into the thickest part of the chicken registers 165°F, about 20 minutes. (Carefully open one package to check for doneness, be cautious of the steam.) Let the packets rest unopened for 5 minutes before serving.
We believe that after five consecutive weeks at GreenLite, you will feel more empowered and in control of your weight. If you are not feeling the program is working for you, just let us know within 30 days and we will refund your initial visit. Conditions apply.*
*This is a conditional promise and only valid if you are present for 5 consecutive weekly visits (including the initial visit) and notify us in writing by the 5th visit. This offer expires 30 days after the initial visit.