Melt butter in a large saucepan over medium heat. Add shallot, potato, corn and garlic, and cook, stirring constantly, until shallots soften, about 2 minutes. Add flour and cook until the vegetables are no longer raw, about 2 minutes.

Slowly whisk the broth into pan, then whisk until mixture is free of lumps. Add milk and half-and-half, frozen corn, salt, and pepper, and bring to a simmer over medium heat. Cook, stirring, until mixture thickens slightly and potatoes are soft, about 5 minutes.

Add the salmon to the chowder; cook for about 4-5 minutes until heated through.

Serve!