Help in finding an Indian curry recipe like the one in this simmering sauce
I really enjoy the Tai Bombay Curry Simmer Sauce, with ingredients found here
but I would like to make it homemade. I have no idea what to search for to find a recipe.
That looks like a very generic tomato based cook-in sauce. I have no idea what might be meant by an "authentic Bomnbay taste". It's about as meaningful as an "authentic Manchester taste" or and "authentic Washington taste".
Here's a link to something similarly generic (and you'll find hundreds of similar ones on the net)
If you're interested in finding a recipe that is more authentic to Maharashtra, then this link might be as good a starting point as any: