Hi Missy.
Please don't attempt to reduce the quantity of onions, if anything, increase! My own base recipe
https://curry-recipes.co.uk/curry/index.php?topic=4596.0 has no carrots or peppers, and is a perfectly good base. A base, is basically a spiced, onion gravy, as long as there are onions, garlic, ginger and some spices, nothing else is required IMO.
Hope that helps.
Ray
