Melt 2 tablespoons butter in a large pot over medium heat. Add the mirepoix and season with salt & pepper. Sauté for 7–9 minutes, stirring occasionally, until softened. Add the garlic and cook for another 30 seconds.

Add the diced potatoes, thyme, paprika, and ground mustard. Sauté, stirring constantly, for 2 minutes over medium heat.

Pour in the chicken stock and increase the heat to high. Bring to a boil, then reduce the heat to low. Cover and simmer for 15 minutes, stirring occasionally and replacing the lid promptly. The potatoes should be tender and easily pierced with a fork, but not soft or mushy.

Remove the lid and stir in the frozen corn. Cook until the corn is heated through, about 2-3 minutes.

In a separate medium pot, melt the remaining 5 tablespoons butter over medium heat. Add the flour and cook, whisking constantly, for 1–2 minutes. While whisking briskly, gradually pour in the milk. Continue whisking until smooth. Season with a tiny pinch of salt & pepper, then cook, whisking very frequently, until nicely thickened.

Stir the milk mixture into the soup over low heat. Cook, stirring often, until the chowder is nicely thickened. Increase the heat slightly if needed, but don’t let it boil. Once nicely thickened, turn off the heat and add the Cheddar one handful at a time, stirring gently between each addition until completely melted. Taste and adjust the salt & pepper as needed.

Ladle into bowls and garnish with bacon if desired. Serve with hearty buttered bread or rolls.