Heat a large rondeau with olive oil over high heat. Working in batches, fry the lamb and mortadella until lightly caramelized. Scoop out each batch and drain in a small colander.
After the last batch of meat is browned, add onion, garlic, and celery and cook for about 2 minutes. Add all herbs (except parsley and mint) and tomato paste. Stir paste into onion mixture and let cook for another 3-4 minutes.
Finally, add the browned meat back into the braising pan. stir well to incorporate then add beef broth. Simmer on low heat for about 40 minutes.
Add the diced carrots and parsley after 40 minutes and let simmer until the carrots are soft (another 30 minutes or so).
The small leaves of oregano and thyme will have fallen off the stems during the cooking phase, pick out the stems and discard before serving. The Bolognese is ready!
To serve, cook your favorite noodles al dente and toss with lamb bolognese. Add a small pad of butter to the finished pasta and finally add half the diced mint. Check and adjust the seasoning with more salt if needed.
Divide the pasta between bowls or serve on a large platter. Garnish with remaining diced mint, a drizzle of excellent quality olive oil and sprinkle with a good strong hard grating cheese. Serve immediately.