Zucchini and Buttermilk Soup

Name: Zucchini and Buttermilk Soup
Ingredients: 1 3/4 pounds zucchini plus 1 small (4-ounce) zucchini, divided; 2 cups buttermilk; 1 tablespoon kosher salt, divided; 6 large hard-boiled eggs, peeled; 5 tablespoons sunflower or extra-virgin olive oil, divided; 1 pound Yukon Gold potatoes, cut into 1/4-inch cubes (about 2 1/2 cups); 6 ounces pickled pattypan squash, cut into 1/4-inch cubes (about 1 cup); 1/4 cup thinly sliced fresh chives; 1 tablespoon finely chopped fresh dill; 6 ounces trout roe or salmon roe; Fresh dill leaves, for garnish