This savory, vegetarian, spicy cucumber soup recipe is thick and flavorful with just the right amount of spicy kick from curry powder and cayenne pepper.
Heat olive oil in a large saucepan over medium heat. Add onion and garlic; cook and stir until very soft, about 10 minutes. Stir in cucumbers, vegetable broth, milk, soy sauce, curry powder, parsley, pepper flakes, cayenne pepper, and sesame oil; bring to a simmer over medium-high heat. Reduce heat to medium-low, cover, and simmer 10 minutes more.
Fill a blender halfway with hot soup. Cover and hold lid down with a potholder; pulse a few times before leaving on to purée until creamy yet slightly grainy. Pour into a pot. Repeat with remaining soup.