1. Slice the zucchini or eggplant into half-inch-thick slices. Peel and slice the onion into half-inch-thick rings. Drizzle one tablespoon of the oil over the chicken and vegetables. Season with salt and pepper. Grill on an outdoor grill or indoors on a grill pan until vegetables are charred and chicken is cooked through.
2. Dice the chicken and vegetables into bite-size prices and mix with the grape tomatoes, greens, remaining oil, salt, pepper, and oregano. Transfer to an airtight container and place the lemon half on top. Seal the container and refrigerate.
3. Before serving, squeeze the lemon half over the salad and toss to combine.
The components can be easily prepped earlier in the week. If you’re firing up the grill for dinner, add an extra chicken breast and some vegetables. When it’s all nice and charred, dice into bite-size pieces and store in a leak-proof container.