This Bolognese features a combination of only two meats, ground beef and sausage, but it produces superior results and it's even better the next day. It's great to freeze and have on handfor months. Slideshow: More Crock Pot and Slow Cooker Recipes
How to Make It
In each of 2 large skillets, melt 1 tablespoon of the butter and 1/2 tablespoon of the olive oil over medium heat. Add the onions and garlic to one pan and the ground meat to the other. Season each pan with 3/4 teaspoon salt and pepper. Cook until the onions and garlic have softened and are lightly browned, about 5 minutes. Add the tomato paste to the onions and cook for another 3 minutes. Cook the ground meat until lightly browned, about 6 minutes.
Transfer the onion mixture and the meat to a slow cooker. Add the chopped tomatoes and their juices, thyme, oregano, basil, and the bay leaves. Cover and cook for 4 hours on high or for 8 hours on low. Discard the thyme sprigs and bay leaves.
Bring a large pot of salted water to a boil; cook the spaghetti until al dente. Drain and toss with the sauce. Transfer to plates, and top with freshly grated Parmesan cheese, a drizzling of olive oil, and chopped basil.