The carbs in your tins of tomatoes are per 100gms - so 2 tins at 400gms a tin will amount to approximately 8 x 4.5 or 36 carbs for the tomatoes alone. The paste is also calculated at 9 carbs per 100 gms and a full jar is about 290gms (?) in weight, making the paste alone about 15 carbs. Unless you use very little onion, it's likely to be 15 carbs worth, which to my mind is the best carb deal of the lot in that curry recipe. I can't imagine a good curry without onions.
Also, you would hardly see 100gms cauliflower - a decent portion to go along with a curry will be 3 times that - or maybe that's just me A good scale will help to see exactly where your carbs are and to eliminate or cut back on the things with the highest per weight of ingredients used.