Wow, thanks all for the wonderful advice and suggestions! All appreciated!
Salt substitute from potassium has not been cleared by the doctor, so I want to be careful before introducing that. As pointed out previously soy sauce is very high in sodium, plus anchovy paste is non-vegetarian, so both are unsuitable. However the other suggestions sound great!
A little oil is okay, and yes frying the spices in oil really does bring out some flavour. A little citrus (not lemon or lime) is okay also but the amchur, tamarind, and/or sumac would probably match the flavours of several foods better than something like orange juice.
True, there is much variety to Indian cuisine (and even more in the rest of the world) and there are many more experiments waiting to be made! Thanks again for all the help!
So, cooking for a loved one, on a very restricted diet. This person especially loves Indian food (particularly lentil/dal or bean soup, and vegetable curry or sabji).
This loved one is dealing with these dietary restrictions:
I'm really struggling especially with how to make Indian food without salt; that's by far the toughest challenge. The no-onions I can get around with asafoetida (hing) - a spice commonly used by Hare Krishna devotees (who don't eat garlic/onions) to replace the onion/garlic flavour. Other items can be skipped entirely. But how do you get around omitting salt in Indian food??