This hassle-free one-pot meal puts healthful ingredients front and center. Barley contains soluble fiber as well as iron, manganese, phosphorus, and thiamin. Feel free to swap out the cannellini beans with great northern or navy beans.
In a 5-quart Dutch oven or large pot, heat 2 tablespoons oil over medium-high. Add onions and garlic and cook until caramelized and tender, stirring frequently, about 15 minutes, scraping up the browned bits (add a little water to the bottom of the pot if it begins to overbrown). Season with salt and pepper.
Add barley and 6 cups water and bring to a boil. Reduce heat; simmer partially covered over medium until barley is tender, about 40 minutes. Stir in beans and chickpeas and cook until heated through, about 1 minute. Remove from heat, stir in the 2 cups whole parsley leaves. Add more water to thin soup as necessary. Season with salt and pepper.
Meanwhile, in blender, combine dill, mint, chopped parsley, vinegar, remaining 1/4 cup oil, and 2 tablespoons water. Puree to desired consistency. Serve soup topped with herb pesto and a dollop of yogurt.