Hi.

I make curries that come in a can or jar from the supermarket. I just
have to brown some meat (usually chicken), add the sauce and heat it.
These curries are always mild or medium strength but I like my curries
hot. What do I need to add to make them spicier without ruining the
flavour? How much spice do I need to use?

I'm guessing that different flavoured curries would be better with
different spieces. I'm interested in increasing the spiciness of:
Butter Chicken
Tandoori
Red Thai
Tikka Masala
Korma
Peanut Curry
Vindaloo
and any others that I might be able to buy in a jar or can.

Thanks for your help.

BobWise