4 to 6 ears corn
4 cups water
1 tablespoon butter or neutral oil, like canola or grapeseed
1 medium onion, chopped
2 medium potatoes, peeled and chopped into 1/4-inch pieces
Salt and freshly ground black pepper
2 tomatoes, cored, seeded, and chopped, optional
1 cup milk (light coconut milk would be a great substitution)
FOR PUREE
2-3 fresh jalapeno chilies
1/4 cup olive oil
1 1/2 tablespoons fresh lime juice
1 tablespoon water
1 garlic clove, minced
1 cup packed fresh cilantro or parsley leaves