Pasta with fennel and Swiss chard in a tomato sauce

This recipe is from my Italian friend. I just wanted to make a nice dish, especially for my partner, and having been an ardent admirer of her culinary skills, I knew I could expect something delectable. She had been to the farmer’s market the day before, and picked up some fennel, nettles, and Swiss chard. She suggested I used sweet Italian sausage for my partner, and I could easily add it later

1 - 14 oz can of crushed tomatoes (use Italian organic brand)
3 cloves of garlic finely chopped
Red pepper flakes
½ bulb of fennel chopped into half inch pieces
I bunch of Swiss chard chopped
I onion finely chopped
2 sweet Italian sausage links (optional)
½ box of penne noodles
Salt
Black pepper
Parmesan

1. Heat some olive oil. Add the onions and sauté till translucent.
2. Add garlic. Now add the fennel and cook till tender.
3. Make the pasta in salty water. I like it al dente.
4. Sauté the sausages, which are diced into quarter inch pieces, on low heat till they turn brown.
5. Add the tomatoes to the sauce. Add Swiss chard, black pepper, and pepper flakes. Cover and cook till sauce is done, around 10-15 minutes. Do not add any salt. Once you add the pasta, which is salty, adjust for salt.
6. Add pasta to sauce.
7. Add the sausages, if you need to.
8. Grate some parmesan on the top.