Check the Asian foods section of your grocery store. It comes in a small can 8 oz can similar to tomato paste. If you still can't find it, a can of coconut milk will suffice - you can usually scrape the coconut cream off the top. If the cream is well mixed, then just adjust your liquid ratios to account for this (less broth to account for more liquid-y coconut component). Cooking is an art, not a science. Have fun with it!