Of the multitudes of Sambar (south Indian Lentil stew) varieties the easiest one is made by boiling vegetables in tamarind water & cooked lentil with a sambhar powdered spice blend added for the characteristic flavor
This is not the simple type.
On days that involve entertaining special guests (a.k.a visiting sons-in-law), Sambars are made with freshly toasted spices & lentils that are ground to a paste as opposed to the fast variety involving the ready made spice blend. My Maternal grandmother's specialty was making a divine sambhar with radishes & coconut. Given that radishes were a rarity 60 years ago in the tiny village she lived in, it makes this family favorite all the more special. The radishes make for the best part of the dish and they tend to be fished out & polished off way before the sambhar does. —Panfusine
Heat the oil in a small skillet and toast all the ingredients (except the coconut, since it tends to brown way faster than the lentils) on low heat till they turn to a reddish hue.
transfer the toasted ingredients onto a plate and then add & toast the coconut till it turns a golden.
Combine all the ingredients and grind to a coarse paste using as little water as possible
Radish coconut sambhar
In a heavy bottom pan, heat 2 tablespoons of sesame oil. Add the scallions & saute till limp. Add the water, tamarind pulp and the radishes . Boil on medium heat until the tamarind loses its 'raw' aroma and the radishes are cooked fork tender. Add salt to taste
Add the ground Masala paste and and combine. bring to a boil, lower heat and simmer on low for 8-10 minutes.
Once the sambhar has cooled down to a warm temperature, stir in the Buttermilk,
Heat the tablespoon of sesame oil, when it begins to shimmer add the mustard, urad dal & the arbol chile. Allow the mustard to sputter, the Urad to turn golden brown & the arbol chile to turn a deep red. Pour over the sambhar.
garnish with cilantro and serve with hot basmati rice drizzled with warm melted ghee.