This easy side dish is winter's answer to the Greek salad. Lightly cooking the tomatoes and garlic sweetens their flavors, while wilting the escarole mellows its bite for this salad recipe.
In a large skillet, heat oil over medium-high. Add garlic, olives, and tomatoes; cook until tomatoes are soft, about 2 minutes; transfer to a plate. Add escarole to skillet and cook, stirring occasionally, until escarole is wilted, about 3 minutes. Season with salt and pepper, return olive mixture to skillet, and stir in vinegar to taste. Serve immediately.