Slice the cucumbers in half lengthwise. Using a spoon, scoop out the seeds and discard. Roughly chop the cucumbers and add to the bowl of a blender along with the yogurt, ½ cup sour cream, lemon juice, vinegar, shallot, dill, parsley, 1 Tbsp Grillville spice and ½ tsp kosher salt. Begin blending on medium speed. With the motor running, slowly drizzle in 1-2 Tbsp olive oil. Continue blending until soup reaches desired smooth and creamy consistency. Season to taste with salt. Cover and refrigerate for at least 4 hours, allowing the flavors to come together. (The soup will thicken as it sits). When ready to serve, whisk together remaining 1 tsp Grillvile spice with remaining ½ cup sour cream. Ladle the soup into bowls and top with a dollop of Grillville-spiced sour cream. Top with a drizzle of olive oil, diced red onion and additional chopped dill. Serve chilled.