Place the cucumber, yogurt, sour cream, lime juice, cilantro, shallot, jalapeño, garlic, coriander, olive oil, salt, and pepper into a blender. Blend until the mixture becomes silky smooth, ensuring all the ingredients are well combined. Adjust the consistency with a splash of water if desired.
Taste the gazpacho and fine-tune the seasoning — add more salt for depth, extra lime juice for brightness, or more jalapeño for a spicier kick. Transfer the soup to a covered container and refrigerate for at least one hour to allow the flavors to meld. It can also be prepared a day in advance for an even more pronounced taste.
When ready to serve, prepare your chosen garnishes. Finely dice the cucumber and shallots, slice scallions or chives, and prepare any herbs or microgreens. If using poached shrimp or avocado, arrange them just before serving for maximum freshness.
Pour the chilled gazpacho into bowls. For an elegant presentation, spoon a swirl or crescent of thinned sour cream across the surface. Top with colorful garnishes — diced vegetables, herbs, microgreens, or edible flowers — to create a visually striking dish.
Serve immediately while cold, accompanied by crusty bread or a light salad for a refreshing, restaurant-quality summer meal.