• 2 tablespoons olive oil
• 2 tablespoons unsalted butter
• 1 large onion, diced
• 2 teaspoons cumin
• 3 tablespoons all-purpose flour
• 4 1/2 cups vegetable broth
• 3 medium potatoes, peeled and cut into 1/4-inch cubes
• 6 cups fresh corn kernels
• 1 teaspoon salt
• 1/4 teaspoon freshly ground black pepper
• 1/8 teaspoon cayenne pepper
• 1/2 cup thinly sliced scallions
• 6 tablespoons tomato salsa (optional)

Directions
Combine the oil and butter in a large pot over a medium flame. Add the onion and cumin and saute for about 4 minutes, or until just tender. Sprinkle in the flour and cook, stirring frequently, another 3 minutes. Add the broth and potatoes, then bring to a boil. Reduce heat to low, cover and cook until potatoes are tender, about 15 minutes. Add the corn, salt, black pepper and cayenne pepper and cook an additional 5 minutes. Transfer 3 cups of the soup to a blender or food processor and puree until smooth. Return soup to the pot and stir until well mixed. Transfer the soup to a bowl and cover with plastic wrap. Refrigerate until cool, about 2 hours. Stir soup well just before serving. Garnish individual bowls of soup with scallion slices. If desired, place a tablespoon of salsa in the center of each bowl. Optional: During the final simmering, stir in 1/2 pound grated cheddar cheese. Heat just until melted, but do not boil.