If there is Idli Batter in fridge then your breakfast & dinner is sorted. I used to eat filling oothapams for lunch too. Growing up I have always seen our fridge filled with different types of batters(Adai,Dosai,Aappam). Chapathi/Paratha are not made very frequently.
When we first moved to UK i didnt carry my grinder and for about a year I was preparing batter in my mixie (Preethi Galaxy) .Luckily bought a second hand grinder from a friend and was using that to make Idli/Dosai batter. Now in Ireland am again using my Indian mixie to make batter. After a few trail and error I can safely say the following measurement, tips will definitely yield a decent fermented batter.
I use the same batter for both Idli & Dosai. The first day after grinding I make idlies and I make Dosais later by diluting the batter with some water.
Brands that I have tried so far that yielded great results :
Idli Rice :Kerala Taste, Heera, Veena’s,Double Horse
Urad Dal :TRS, Heera,East End, Natco
Incase if you dont find these brands in your place, use the ones that are available in your country. Just follow the tips and once you start preparing the batter at home, based on the results you can try to alter the proportion, techniques etc.