Prepare your lamb shoulder for braising. I do this by cutting overly excessive fat, cutting it into big chunks, rinsing with cold water and patting dry with paper towel.
Place the oil in a pot and turn to high heat. When hot sear all the lamb shoulder pieces. (See note 1)
Once seared turn heat to low and add the remaining ragu ingredients. Fill the pot with water until it goes up 1/3 of the lamb shoulder meat. Place the lid on the pot and let the magic happen.
I tend to check on the ragu from time to time to make sure the moisture level is ok. If needed I top up to the appropriate moisture level. All up it should take between 3 - 4 hours for the ragu to become fork tender.

When it reaches fork tenderness take the meat out of the sauce and shred it before placing it back in ragu sauce at ultra low heat.
Cook the pasta al dente in salted water.
Reserve a tiny but of the pasta water before straining the pasta.
Return the pasta to a frypan and add ragu to it ensuring all the pasta strands are getting coated with the ragu. This is where the pasta water helps bind and coat the pasta so if you are struggling to get equal coating add the paste water to help make it more fluid. The heat from the frypan will help it evaporate off leaving perfectly coated pasta.

Place in serving bowls and garnish with parmesan and fresh chilli (optional).
Bah bah!!!
Note 1: If using a slow cooker just chuck all the Ragu ingredients into a slow cooker pot and set to slow cook for 16 hours. No need to sear.