Tender and Juicy Slow-Cooker Meatballs Recipe

Name: Tender and Juicy Slow-Cooker Meatballs Recipe
Prep time: 1 h
Cook time: 8 h
Total time: 9 h
Cuisine: European, Italian, Mediterranean
Ingredients: 3 slices white bread, crusts removed, roughly torn; 1/3 cup buttermilk, plus more as needed; 1 large onion, minced (about 1 1/2 cups), divided; 12 cloves garlic, finely minced, divided; 2 ounces grated Parmigiano-Reggiano, grated, plus more for serving; 1/2 cup loosely packed fresh parsley leaves, minced; 4 teaspoons kosher salt (18 grams); Freshly ground black pepper; 2 large eggs; 2 teaspoons dried oregano, divided; 1 pound ground beef (at least 25% fat); 1 1/4 pounds ground pork (at least 25% fat); 1/4 cup extra-virgin olive oil; 3 (28-ounce) cans whole peeled tomatoes, crushed by hand; 1/2 teaspoon red pepper flakes; 1 sprig fresh basil; Cooked pasta, for serving; stand mixer, slow cooker