Ambat means Coconut based gravy which has a seasoning of fried Onion. Ambats can be made of vegetables or grams/grains. If using grains they are usually sprouted and used.
Ghashi means simple Coconut based gravy which has Mustard and Curry leaves seasoning.
Koddel/Bendi means Coconut based gravy which has fried Garlic seasoning.
Tamblis are usually made with Coconut and yoghurt (Plain). Though some of them may not be yoghurt based. It is usually served cold as it is not boiled.
There are some more exceptions like kadhi etc but these are main classifications. Based on different regions ambat or ghashi is used to refer to the same dish. But this is how we classify at home.
Coming to this dish I made this few days back. Keerlanu means sprouted, Mooga ambat means green gram in Coconut based gravy with fried Onion seasoning. This is not made very spicy and is mild in taste. Here is what's needed:
2 cups sprouted Green gram washed and de-skinned. (It is better to remove the skin while washing else while cooking the skin tends to float at the top)
1 cup grated Coconut
1 small Potato cubed
6-7 fried red Chillies (Reduce if the Chillies are spicy)
Tamarind - small Gooseberry sized
One medium sized Onion chopped finely
Oil for seasoning
Salt to taste
1) In a vessel add the cleaned Sprouts, half of the chopped Onions and cubed Potato along with enough water and boil it.
2) Meanwhile finely grind grated Coconut, red Chillies, Tamarind and Salt with little water.
3) When the Potato is boiled and the sprouts turn slightly soft add the ground paste and let it boil. Check for salt. Add water if the gravy is too thick.
4) Let it boil for 5 mins on medium flame. Switch it off. Heat oil in a seasoning pan and add the rest of Onions and fry until golden. Pour this seasoning over the gravy. Mix and serve hot with Rice.
Variations: In North Canara while making Ambat, 1/4 tsp of Fenugreek/Methi seeds and 2 pinches of Turmeric powder are fried in little oil until methi turns slightly pink. This is added along with grated coconut, red chillies, tamarind and salt and ground fine. Take care not to burn the methi seeds or turmeric powder as it will make the gravy bitter.
There may be many other types in which Ambats are prepared but these are the 2 types that I have known so far. Please let me know if there are any variations.