Sauté the chopped onion and red pepper in 2 tbsp butter for 5 min.
Sprinkle with ¼ cup all-purpose flour and ½ tsp dry mustard, stirring constantly.
Stir in 2 cups chicken or vegedata broth, ½ tsp paprika, and ¼ tsp hot red pepper flakes and pepper. Stir constantly, until slightly thickened, 4 min.
Stir in 2 finely diced potatoes and 1 ½ cups corn kernels. Cover and simmer, stirring often, until potatoes are tender, about 15 min.
Add 2 cups milk. When hot, stir in 1 ½ cups grated old cheddar until melted.
Serve sprinkled with sliced green onions.