1. Sauté onions and peppers in butter until soft. Add mushrooms and garlic and cook until mushrooms release their liquid. Add seasoning to taste.
2. Add flour and mix well. Slowly add enough half and half to form paste and mix well. Continue adding half and half until thick sauce forms. Add cream of mushroom and mix well.
3. Cook until soup is well dissolved. Add the remainder of half and half with corn and shrimp and crabmeat. Heat while stirring to avoid sticking.
4. Garnish with chopped green onions and parsley.