Preheat the oven to 350ºF.
Combine the squash, zucchini, eggplant, onion, and garlic in a large mixing bowl. Add the oil, 1/2 teaspoon of the salt, and 1/4 teaspoon of the pepper. Toss to coat evenly.
Put the mixture in a baking pan and roast until the vegetables are soft, about 30 minutes. Cool, then chop into 1/2-inch dice.
Combine the butter and pecans in a large nonstick skillet over high heat. Cook, stirring until they are toasted and golden brown, about 3 minutes. Add the vegetables and cook for about 1 minute, stirring once or twice. Add the remaining 1/2 teaspoon salt and 1/4 teaspoon pepper and stir to mix. Serve hot.
Yield: 10 servings