Loved the flavour of these, and the pleasant little bit of heat, I made them for a dinner party appetizer, everyone loved them, a huge success! I had no tarragon vinegar so I subbed with 2 tablespoons of balsamic vinegar. Rather than serve them on toasts I served them in a dish with the sauce and with tooth picks, worked very well. Thanks for posting, I will make them again, next time I will try them on the toasts..
For flavor this is a 5 plus there were a couple of things that were not covered in the instructions like when to toast the bread slices I may have done it differently - I have found that marinating cooked prawns in a vinegar based marinade can toughen them but I wanted the great flavor so I marinated them for 1 1/2 hrs,saved the marinade - I buttered the baguette slices and toasted them just before serving, placed two prawns on each slice. I placed all the chopped garlic, shallots etc with some of the liquid in a bowl and served it along side of the prawn toast. Then we could add a tsp of the the lovely garlic mixture to each one, one at a time This recipe is not to be missed - Thanks Oolala for a lovely appy with my Sunday Martini