Instructions

1. Preheat oven to 350ºF.
2. Cook the pancetta: Place the diced pancetta in a large pot. Turn the heat to medium. Stir occasionally for 4 to 5 minutes until the fat renders and the pancetta browns. Remove from the pot and transfer to a large bowl.
3. Brown the short ribs: Pat the short ribs dry and season all over with salt and pepper. Place the short ribs in the pancetta fat and cook over medium-high heat for 3 to 5 minutes per side until browned all over. Transfer to the bowl with the pancetta.
4. Cook the aromatics: If needed, add another teaspoon or two of oil and turn the heat to medium-high.
5. Add the onion, celery, and carrots and cook for 5 to 7 minutes. Season the vegetables with salt and pepper.
6. Melt the butter into the onions. Add the garlic and cook for 45 seconds. Add the tomato paste and cook, mashing it into the aromatics, for 2 minutes until it begins to deepen in color. Be careful not to burn the garlic.
7. Pour in the red wine and turn the heat to high. Whisk the wine into the paste and continue until the wine begins to boil. Boil for 5 minutes until it just begins to reduce.
8. Simmer the ragù: Add the tomatoes and bring to a boil. Stir in all of the meat from the bowl. Season the sauce with salt, pepper, sugar, and crushed red pepper. Add the rosemary sprigs in whole (you will remove them later).
9. Reduce heat to low. Cover and transfer to the oven for 2 hours, or until the short ribs can be shredded easily with a fork. Check the short ribs occasionally to ensure they are not sticking to the pot, and add more liquid as needed.
10. Shred the short ribs: Remove the ragu from the oven and carefully remove the top. Discard the rosemary. Shred the short ribs and mash the whole tomatoes. Turn the heat to medium-high and let the ragù bubble uncovered for 15 to 20 minutes. Add beef stock in ¼ cup increments if the liquid evaporates too quickly. Taste and season. 
11. Prepare the ricotta mixture: Combine all of the ingredients for the ricotta mixture in a bowl. Use a whisk or a hand-mixer and mix until combined. Season with salt and pepper to taste.
12. Prepare the béchamel sauce: Warm the milk in a microwave-safe bowl or glass measuring cup for 1 to 3 minutes. Set aside.
13. Melt the butter in a large saucepan. Once bubbly, add the flour and stir into the butter for 1 to 2 minutes.
14. Add the milk in 1-cup increments, whisking after each addition. Continue adding the milk until it has all been incorporated. Continue cooking for 5 to 10 minutes until the béchamel thickens. Season with salt, white pepper, and nutmeg. Keep warm.
15. Assemble the lasagna: Preheat oven to 350ºF.
16. Grease a 9×9 baking dish. Add ⅓ cup of the béchamel and use a rubber spatula to smooth it into an even layer.
17. Place 2 lasagna sheets over the béchamel, avoiding overlap if possible. Use kitchen shears to trim the lasagna if they are too long.
18. Spoon ½ of the ricotta mixture on top of the lasagna noodles and use the rubber spatula to smooth it out. Pour a few ladles of the ragu on top of the ricotta. Finish with ½ of the béchamel sauce.
19. Place two more lasagna sheets on top. Add the remaining ricotta mixture and a few more ladles of the ragu. Add the remaining béchamel sauce on top.
20. Place the final two lasagna noodles on top. Add a few ladles of the ragu on top and smooth it out. Sprinkle the mozzarella cheese on top.
21. Bake the lasagna: Cover the lasagna with foil. Transfer to the oven for 45 minutes. Remove the foil and bake, uncovered, for 15 minutes. You can also broil the lasagna for 2 to 3 minutes if you like extra browning on the cheese.
22. Allow the lasagna to cool for 15 minutes. Slice into portions and garnish with basil leaves, if you like. Enjoy!