3 tablespoons olive oil
1 tablespoon butter
1 medium onion, halved lengthwise and thinly sliced
1/2 teaspoon sea salt
2 pounds of mix of yellow summer squash and zucchini, halved and thinly sliced
2 carrots, thinly sliced
1 sweet potato, peeled, halved, thinly sliced
4 cups low sodium chicken stock
Fresh ground black pepper
Heat oil and butter in large, heavy wide pot over medium heat. Cook onion with salt, stirring until it begins to caramelize (about 8 minutes). Add remaining vegetables and stock and bring to a boil. Reduce to a simmer and cook, partially covered, until vegetables are very tender, about 20 minutes. Let cool for 10 minutes off the heat and then puree until desired consistency. Season with additional salt and pepper to taste.
