Cabbage poriyal is a mild accompaniment in a lunch menu. I have added peas to it, you can follow the same method for plain cabbage poriyal too. Step by step pictures detailed post.
I am having cabbage peas poriyal in my drafts for almost three years now. I kept it for so long that I never felt like posting this simple recipe. But when I made this poriyal last week, again freshly clicked to make this post. This could help beginners in cooking who wants to learn basic south Indian cooking (TN).

Poriyal in our home means mild spiced vegetable accompaniment, with a must addition of scraped coconut added towards the end. It should be looking fluffy, dry and separate(udhir udhirya). Kari/curry (not the gravy curry) usually made spicy without coconut either like my potato curry or with onion tomato base (like my vendakkai curry). Mom makes poriyals mostly and she even includes coconut in potato. I learnt onion tomato based curry only from my mami (MIL), also making curry without coconut.
I eat poriyals mostly mixed with rice and ghee/ sesame oil, as I am bad when it comes to eating vegetables🙄. So is Aj when it comes to poriyals. He doesn’t like coconut added mild poriyals, so same way I give him too, that is mix rice with ghee and poriyal so that he consumes that vegetable too.
The draft I have is my mami’s method of making cabbage poriyal. Both my mom and mami boils veggie in water with our sambar powder and salt, drain water, then prepare poriyal with the vegetable. I don’t know🤷🏻‍♀️ why waste the nutrients, but I too learnt the same from them and blindly followed for a long time. Even now, certain poriyals I do the same, but trying to avoid as much as possible.
My mami makes cabbage poriyal by boiling chopped cabbage in water with sambar powder and turmeric, ginger, salt drains water once cooked and then proceed to prepare poriyal. She takes out the ginger, yet the cabbage will have ginger flavour in it.
Mom makes same way when it comes to cooking process, but just boils with salt. Her poriyal will be white not yellow and she uses moong dal while boiling cabbage. Green chilli will be added along with onion for spice and it gives a nice flavour too.

I kind of mixed these both methods for this post. I love shredding cabbage in a mandoline slicer as it is easy as well as looks good. Basic thing to be kept in mind while making vegetables, do not over cook and make it soggy. Also never let the onion or vegetable get browned, this will help the poriyal look nice, than dull in colour. I love adding lots of onion for cabbage poriyal as I love that way.

Step by step pictures:

1. Shred cabbage in a mandoline slicer. Chop onions finely, slit green chilli and cut into two. Peel ginger and keep as such as a piece. 



2. In a kadai/ pan, heat oil, splutter mustard, add urad dal give it a fry. Drop curry leaves in it, followed by chopped onion, slit green chillies, ginger. Fry for a minute just to make it translucent, without browning/ changing colour.



3. Add green peas and stir fry for a minute more.



4. Shredded cabbage goes into this along with turmeric, required salt. Stir fry for 2 minutes until cabbage shrinks. Colour should not change. Sprinkle ¼ cup water and cook covered for 4 mins.



5. Once done, take out the ginger and add scraped coconut. Cook for a minute or two. until the poriyal is dry.

Serve as accompaniment for rice, sambar.