At least two hours before serving, combine the marinade ingredients in a nonreactive bowl. Reserve 3 tablespoons and set aside. Add the chicken, cover, and refrigerate 2 hours up to overnight.
Prepare the Vegetables, slice the zucchini into rounds about 1/2 to 3/4 inch thick and cut the peppers into chunks about the same size as the zucchini slices.
Cook the rice according to package instructions.
Heat the grill to medium-high. While it heats, whisk together the yogurt and reserved marinade plus 2 tablespoons lemon juice for the sauce. Refrigerate until ready to serve.
Grill the chicken about 8 minutes per side, until it reaches an internal temperature of 165°F. Transfer to a cutting board and let rest 5 minutes before slicing.
While the chicken cooks, place the zucchini and pepper on the grill and cook for a few minutes until soft and slightly charred.
Divide the rice, vegetables, and sliced chicken between bowls. Drizzle with yogurt sauce.
Notes
Store leftovers separately in airtight containers in the fridge up to 3 days.Reheat in a skillet or microwave, or serve cold in a sandwich or wrap.