I am not a daanger patchadi fan. But here is a simple recipe. I am sure some others will also share one by and by.
Dry roast a cup of urad dal for a few minutes and set aside to cool. Blend two cups of fresh yoghurt with one ripe tomato, an inch long piece of cucumber and 6 fresh curry leaves and one green chili. One tsp Tabasco sauce or chili sauce.
Dry grind the urad dal (I use my magic bullet) and whisk it into the yoghurt mix. Add salt to taste and splutter some mustard and cumin seeds and a 1/8 tsp hing in some canola/ sesame blend and add on top. Add some fresh grated coconut as a garnish.
Purists will tell you this is not daanger patchadi. But try it and decide for yourself.