Place the bratwurst sausages in the Sizzling Sausage Grill and cook until done.
While the sausages are cooking, make the sauce. Place the beer and brown sugar in a pot over medium high heat; bring to a boil. Lower the heat and simmer for 10-15 minutes or until mixture is reduced and thickened. Whisk in the mustard until smooth.
Whisk the cornstarch with 1 tablespoon cold water and pour into the beer mixture. Bring the beer to a boil and cook for 1 minute, stirring constantly, until sauce is thick.
Slice the sausages into 1 inch pieces and add them to the pot with the sauce; toss to coat. Sprinkle with parsley and serve.