I have been using Julian Curry to go base, and per 300ml base it has 2 Table spoons of vegetable oil so it's
Per 100ml = 829kcal got off a bottle
829 / 100ml = 8.29 per ml
8.29 * 30ml = 248.7 cal
30ml is equal to 2 Table Spoons
So his base sauce has 249 calories in oil.
It is more as it's hard to count the onions and other stuff
The garlic and ginger has a small amount of oil too

I got this from the internet
29 calories in 1 small raw onion
44-46 calories in 1 medium size onion (2?" diameter)
63 calories in 1 large onion
64-67 calories in 1 cup of chopped onion
I only use 20ml oil when I start my curry