Prepare the Ingredients: Peel and dice the potatoes and chop the onion. If using fresh corn, cut the kernels off the cob; otherwise, use frozen corn.
Cook the Onion: In a large pot, melt the butter over medium heat. Add the chopped onion and cook for about 5 minutes, until soft and translucent.
Make the Roux: Stir in the flour and cook for 1-2 minutes, stirring constantly to avoid burning.
Add Corn and Potatoes: Add the diced potatoes and corn to the pot. Stir to combine with the onion and flour mixture.
Add the Broth: Pour in the chicken or vegetable broth, stir, and bring to a boil over medium-high heat. Once boiling, reduce the heat and let it simmer for 15-20 minutes, or until the potatoes are tender.
Add Cream: Stir in the heavy cream and simmer for another 5 minutes. Season with salt and pepper to taste.
Serve and Garnish: Ladle the chowder into bowls and garnish with fresh parsley or chives if desired. Serve hot.