Pasta Bolognese with Chicken sausage

Bolognese Sauce is a meat(beef) based sauce for pasta (Ragù as known in Italian) originated in Bologna, Italy. The people of Bologna traditionally serve their famous Ragù with freshly made tagliatelle(Thick ribbon shaped pasta), but this sauce also pairs very well with other pastas and with Spagheti, too.
The authentic version contains these ingredients : minced beef, pancetta or bacon, onions, carrots, celery, tomato paste, meat broth, wine, chicken liver can also be added and freshly grated nutmeg and grated parmesan cheese to garnish. It's not a tomato based sauce but a meat based. Traditionally very little tomato sauce is used in this recipe. Main ingredient here is meat.
I created this bolognese sauce with chicken sausages in stead of minced beef as I don't eat beef. It incorporated very well in the sauce as I expected. All the other ingredients I used as in the authentic version requires.

Ingredients :
Chicken sausage : 4-5 nos.
Onion(medium) : 2(finely chopped)
Carrot : 1 (diced)
Celery stick : 1(diced)
Potato(medium) : 1(diced)
Garlic : 2 cloves(grated)
Toamto paste or puree : 2 tblsp.
Fresh green or red chilli : 2(finely chopped)
Chicken stock : 1/2 cup
Salt and black pepper to taste
Freshly grated nutmeg : 1 tsp.
Olive oil : 3 tblsp.
Pasta of your choice (I used Penne pasta)
Dried or fresh Italian herbs(oregano, thyme, parsley& rosemary) &
Freshly grated parmesan cheese for Garnishing

Method :

Boil water in a heavy based saucepan and throw sausages in that and boil them for 4-5 minutes. Add a pinch of salt in that.
Meanwhile, cook pasta in boiling salted water until tender.
Heat oil in a pan, fry sausages in that until light brown. Drain on a paper towel. When they are slightly cooled, chopped them finely. Keep aside.
In the same pan, add onion, garlic and chopped chillies. When onions turn light brown, add chopped carrot, potato and celery. Brown them and then add choppd sausages. Try to mash them as much as you can with the back of your ladle. Stir fry for 2-3 minutes, then add tomato puree or paste, mix well.
Then pour the stock. Season with salt, pepper and nutmeg. Bring to boil, half-covered until sauce thickens, stirring occasionally. Add cooked pasta and toss with the sauce. Check the seasoning, add more salt and black pepper if needed.
Now add dried or fresh herbs and toss well with the pasta.
Garnish with little extra herbs sprinkling on top of the dish and with greated paremsan, if you like. Serve immediately warm.