Heat olive oil in a 12" skillet over low heat. Add shallots and cook, stirring, until softened and fragrant but not browned, about 2 minutes. Add garlic & cook another minute. Increase heat to medium and add tomatoes, salt & pepper. Cook, stirring to coat, until tomatoes begin to burst, about 4 minutes.
Smash some of the tomatoes with the back of a wooden spoon to start to create a sauce. Continue to cook, stirring occasionally, until a chunky, thickened sauce develops, add the parsley & cook 10–12 minutes. Stir in the olives at the last few minutes of cooking time.
Taste and adjust seasoning.
Serve over pasta.