This succotash, usually a combination of corn, lima beans and other beans, (though I dropped the last ingredient in favor of chiles and tomatoes) is delicious on its own. I was serving it for an event and decided to turn it into a gazpacho, served in small cups. Enjoy!
In a large saute pan, heat the oil and butter over medium heat until the butter is melted. Add the onions and garlic and cook, stirring often, until fragrant and sweating, about 5 minutes. Add the vegetables and herbs, season with salt and pepper, and cook, stirring often, until everything is tender, 5 to 10 minutes.
Reserve about 1/2 cup of the succotash for garnish, then transfer the rest to a blender. Add the buttermilk and blend until smooth. With the blender running, add the milk slowly, until smooth and thinned to your desired texture.
Refrigerate the gazpacho and reserved succotash until chilled, about a couple hours. Pour the gazpacho into cups and garnish with the reserved succotash.