Combine basil, oregano, lemon juice, olive oil and minced garlic in a large food storage bag; add cut-up chicken, coat evenly with the marinade and refrigerate for at least 1 hour, or up to 2 days.
Cut zucchini, pineapple and onion into 1/2-inch chunks. Brush the skewers lightly with olive oil and arrange with chicken, pineapple, zucchini and onion. With a pastry brush, brush the assembled kebabs with remaining olive oil. Sprinkle with salt and pepper.
Set your gas grill or grill pan to medium-high heat and arrange kebabs evenly. Cook for 10 to 12 minutes, turning often, until vegetables are tender and chicken is cooked through. Carefully remove kebabs from grill or grill pan with an oven mitt.
Serve with tzatziki sauce, if desired. Also, you can serve the kebabs over rice, with basil pesto potato salad, or your favorite Mediterranean side dish.
Tzatziki Sauce
In a bowl, combine the yogurt, dill, grated cucumber, lemon juice, minced garlic, and salt. Stir ingredients together and serve, or cover and refrigerate until ready to use.