In a 12-inch sauté pan, add olive oil on medium to high heat. When hot, add onions and some salt to brown them about 8-10 minutes. Add the garlic and red pepper flakes for 1 minute. Pour in the wine and make sure to scrape up all of the brown bits from the pan. Add clam sauce and chopped clams, bring to boil and simmer for 10-15 minutes on low, stirring occasionally. Season with salt and pepper to taste. Meanwhile, steam the clams for about 10-15 minutes until they open up and throw the shrimp in for the last 6 minutes. Remove clams and put into separate bowl and place shrimp in the sauce mixture to coat. Boil the pasta as directed. Place pasta in serving dish and pour over sauce and shrimp. Place clams on top for presentation. Sprinkle with chopped parsley.