In large skillet, heat olive oil over medium-high heat. Add onions, cut into strips, and sweet peppers (assorted colors), cored and cut into strips; saute until softened, 10 minutes.
Add garlic, salt, black pepper and tomatoes with juice, broken up; simmer 10 minutes over medium heat, stirring occasionally.
Add sea scallops and tuck into peppers; cook, turning scallops over once, until scallops are just cooked through, about 6 minutes.
Stir in flat-leaf parsley leaves. Serve with pasta.