These ingredients are only suggestions; use whatever is ripest, from the market or your own garden.
In a large pan over high heat, saute eggplant and rosemary in oil for 5 minutes. Add squash and zucchini, and saute a few minutes more. Salt and pepper lightly. Add fennel, onion, and garlic, and saute until soft. Add peppers, reduce heat, and cook for 4 minutes. Mix in thyme and orange zest; add tomatoes and vinegar. Cook for 5 minutes. Remove from heat, and adjust seasonings with salt, pepper, vinegar, or oil. Cover, and keep warm.
Cook penne in a large pot of boiling salted water, according to package instructions, until al dente. Drain. Toss with the vegetables. Serve hot or cold.