Heat 2 tablespoons of olive oil in a large (12-inch) skillet over medium-high heat. Add the ground sirloin and cook, crumbling the meat with a wooden spoon, for 5 to 7 minutes, until the meat has lost its pink color and has started to brown. Stir in the garlic, oregano, and red pepper flakes and cook for 1 more minute. Pour 1 cup of the wine into the skillet and stir to scrape up any browned bits. Add the tomatoes, tomato paste, 1 tablespoon salt, and 1 1/2 teaspoons pepper, stirring until combined. Bring to a boil, lower the heat, and simmer for 10 minutes.