Okay I give up, I've tried and failed about 8 times now frying prawns but they never are succulent. The recipe that I want to get done is pretty simple:   De-vein. Salt the prawn for some time and allow it to marinate. Wash them.  Fry them in some oil till they turn pink. Add onion, chillies, ginger, garlic. Some turmeric. Some tomatoes.    The cuisine is Goan if it's of any help.  This is exactly what mum does and somehow it turn out great. The only things different that I'm doing are:   The original recipe uses coconut oil, I'm using sunflower I'm using frozen prawns because i cant get hold of fresh prawns.   I don't think any of this should affect the dish. Anyway, what always happens is that the prawns are either too chewy or too dry (opposite of juicy).  What am I doing wrong here?  How do I know if the prawns are just cooked right?  Should I be using low or high heat?  Any other tips for getting really juicy fried prawns? 
Try Caraway as a substitute for Cumin. It has a similar flavour profile, just a little more intense. Some people prefer the flavour of Caraway and use it in all their recipes instead of Cumin.  I cannot tell you if you will be allergic to this herb, just like I don't know if you'll be allergic  to any other herb because you'r allergic to cumin. Caraway comes from an entirely different plant. It belongs to the same family as anise, fennel, dill, cumin, licorice, and coriander. So if you're allergic to all of those (i.e. the entire family), you're probably allergic to Caraway too. But if your allergy is restricted to cumin, you could give caraway a try. 