1 Start With The Tomato Sauce, Which Will Simmer While You Prepare The Meatballs. Heat Olive Oil In A Large Skillet On Medium Heat. Add The Onions, Carrots, Celery, And Parsley. Stir To Coat With The Oil, Reduce The Heat To Low And Cover The Pan. Cook For 15 To 20 Minutes Until The Vegetables Are Soft And Cooked Through. Remove The Cover, Add The Garlic, And Increase The Heat To Medium High. Cook The Garlic For Half A Minute, Then Add The Tomatoes (If Using Whole Canned, Break Up With Your Fingers As You Add Them To The Pan.) Add The Tomato Paste And Basil. Season With Salt And Pepper. Bring To A Low Simmer, Reduce The Heat To Low And Let Cook Uncovered Until Thickened While You Prepare The Meatballs, 15 To 30 Minutes. Pur