There's a zillion recipes for bolognese sauce, but this one worked well for me. Some people add cream at the end, but I find I don't like that as much. This one's really good if you can find hot pepper paste (usually associated with Hungary, but I have a Peruvian brand that's excellent). You can make it entirely un-spicy if you like, too.
2 large cans whole tomatoes, ideally Red Gold brand (or you can use 1 can puree and 1 can crushed if you don't have a blender)
1 lb ground beef
1 c. red wine
1/2 c. beef broth
1 onion, minced
1 tsp. red pepper flakes
2 tsp. oregano
1 tsp. dried basil
1 tsp. ground black pepper
1 tsp. fennel seeds (optional)
3 Tbsp. salt
3 Tbsp. olive oil
2 Tbsp. red pepper (or tomato) paste
2 Tbsp. flour
1/2 c. water from boiling pasta
2 cloves garlic, crushed
Brown the ground beef and chop it up with your stirring device so that it's finely textured. If you have a pressure cooker, add 1/2 c. red wine and the 1/2 c. beef broth and cook for 15 minutes. If you don't have a pressure cooker, add the wine and broth and allow it to simmer 20 minutes.
Release pressure in cooker, if using. Cook away all the broth and then add the onions and spices and cook until the onions begin to soften, ~5 minutes. Add the flour, stir, and cook 2 minutes, then stir in the red pepper paste and cook 2 minutes more.
Drain one of the cans and save the liquid for another day. Coarsely chop the tomatoes from the can and set them aside to add to the sauce later. Blend the remaining can, liquid and all, until it's a fine puree (or just use pureed tomatoes, but blend them finer if you can). Add the pureed tomatoes, remaining 1/2 c. red wine, and olive oil to the pot and allow the sauce to simmer for 30 minutes. Add the remaining chopped tomatoes and the pasta water* and continue to simmer for another 30 minutes, or until the volume is reduced by half and the sauce is velvety.
*While it's simmering, cook the noodles in well-salted water, and reserve 1/2 c. of the water from boiling--this, along with the flour and the olive oil, will help emulsify the sauce.
At the very end, add the crushed garlic and cook the sauce one more minute. Adjust the salt if necessary. Serve over pasta, with a generous helping of parmesan on top.