Charred Corn Soup - SippitySup

Ingredients

• 2 tablespoons unsalted butter
• 8 ears fresh corn (kernels removed)
• 5 cloves garlic (peeled and minced)
• 3 stalks celery (small diced)
• 1 teaspoon ground cumin
• ½ teaspoon ground coriander
• kosher salt (as needed)
• 2 cups small diced peeled pumpkin (or other orange-fleshed winter squash)
• 2 bay leaves
• 2 teaspoons fresh lime zest
• 1 teaspoon chipotle chile powder (or to taste)
• 4 cups water (or more as needed)
• 8 ounces sour cream (or more as needed, divided)
• lime wedges (as needed)
• 6–8 crisp tostada rounds (or tortilla chips)
• crumbled cotija cheese (as needed)
• fresh cilantro (as needed)