In a vessel, add chopped beans, salt, turmeric and water.

Cover and cook till beans are cooked and all water is used up. Keep aside.
Next in a blender jar, take soaked dal, salt, turmeric powder, hing, dry red chilli and minimum water.

Grind into a course paste. Keep aside.
Next heat a kadhai, add oil and heat it. Splutter mustard seeds, cumin seeds. Add urad dal, dry red chili and curry leaves.

Now onto it add the dal paste. Keep flame slow. Cook the dal till it's colour is changed and it is nicely crumbly. It gives a nice aroma too.

Now add the steamed beans into the dal crumbs. Mix and cook at slow flame for some more time, till all the flavours get nicely combined.

It's ready...Beans paruppu usli or beans cooked with flavoured dal is ready...
My mother in law makes plain usli using chana dal in the same method. It too tastes superb.