Heat 1/4 cup of olive oil in a large pot over MEDIUM heat. Add the diced onion and cook until translucent.
Incorporate the ground chuck and ground pork, breaking the meat apart with a spoon. Cook until browned.
Stir in the minced garlic and red pepper flakes, cooking for another minute until fragrant. Pour in the white wine, scraping any browned bits off the bottom of the pot. Add the hand-crushed plum tomatoes, season with salt and pepper.
Let the sauce simmer for 30 minutes. Finish by stirring in the 5 chopped basil leaves. Set aside.