Heat a Dutch oven over medium-high heat. Coat pan with cooking spray. Add bell pepper and 3/4 cup green onions, and sauté 4 minutes or until lightly browned.
Increase heat to high; add corn, water, seafood seasoning, thyme, red pepper, and potatoes; bring to a boil. Cover, reduce heat, and simmer 10 minutes or until potatoes are tender. Remove from heat, and stir in half-and-half, chopped parsley, and salt. Place about 1 1/2 cups soup in each of 4 bowls; sprinkle each with 2 tablespoons cheese and 1 tablespoon green onions.