In a pot, heat butter together with oil and sliced garlic. Sauté for about 1-2 minutes. Then add diced onion and sauté until translucent for about 2-3 minutes. Add spices and constantly stirring, sauté for about 2 minutes.
Cut corn kernels from the cobs by standing them upright on a cutting board, add 2/3 of the kernels to the pot (reserve 1/3), discard empty cobs. Sauté corn for about 2-3 minutes, stirring occasionally, then pour in wine and evaporate. Pour in broth and bring to a boil. Season with freshly ground pepper and salt if needed. Cover the pot and simmer for 30 minutes on moderate heat.
Blend in a standing blender to a smooth creamy soup. Pour back into the pot and bring to a boil. Add peeled and diced potatoes, reserved corn kernels and simmer the soup covered for about 20 minutes until potatoes are soft.
Peel 150 g shrimp out of their shells, remove tails, clean out intestines (if shrimp were not previously cleaned), cut meat into pieces. Add them to the soup and simmer for about 2-3 minutes. The remaining shrimp for garnish should also be cleaned, leaving only the tails. Fry them in butter with oil, seasoning with salt, pepper and a bit of chili. Before serving, sprinkle the soup with coriander.
