2. For Coriander leaves, wash, clean and keep them in de-freezer in a a box which is having hole. That is you can keep coriander, methi leaves in strawberry boxes. Whenever you need remove from the freezer and put them on the dish. But your fridge must be a FROST FREE ONE.
Or you dry them thoroughly and store them in air tight container. whenever you need them crush them and add. That is all. Like this you can do for coriander leaves, curry leaves, pudina and also methi leaves. This is easy way to store.
and you can use those dry crushed leaves to make good lassi also.
3. I generally keep many months. No problem for me.
4. Yes you can make tomato puree and use them for rasam. But generally I wont use preservative. so I will keep tomato puree for only 2 days. If you use preservatives you can keep them for some more days.
Rest in next post.