In a hot sauté pan add 1 Tbsp. of olive oil and sauté shrimp and scallops with salt and pepper for 3-4 minutes (until no longer translucent). Drizzle with1 Tbsp. of lemon juice and set aside. In the same sauté pan add remainder of olive oil and sauté onion and garlic (until translucent). Add remaining ingredients except for fresh parsley. Reduce heat and cook uncovered for 10 minutes. Add the shrimp and scallops and stir in the sauce. Place the clams on top of the sauce and cover. Continue cooking until the clams have opened up. Discard any unopened clams.