This is a versatile dish, as you can start out with fresh or frozen shrimp, cooked or raw. It can serve as an appetizer for 4, but I much prefer it as a dinner for 2. I have never made it with hot curry paste, so cannot say how that would taste.
If you're starting off with frozen shrimp, don't thaw them; place in a sieve and rinse under cold running water until the ice crystals are melted; pat shrimp dry with paper towels; you can also use frozen cooked shrimp in this recipe as well, the recipe indicates the 2 different cooking methods.
No matter what kind of shrimp you start out with, cooked or raw, place peeled shrimp and curry paste in a bowl and, using your hands, rub shrimp with curry to evenly coat; it is important that you've dried the shrimp well so the curry paste sticks.
Core tomatoes, slice in half, then squeeze out and discard juice and seeds.
Coarsely chop tomatoes and set aside.
If using raw shrimp: place a large non-stick skillet over medium-high heat and, when hot, add shrimp.
Stir-fry just until shrimp are a bright coral colour (this will only take 3 to 4 minutes); if shrimp stick, add a wee amount of butter to pan.
If using frozen or fresh precooked shrimp: stir-fry only for 2 minutes, just until shrimp are heated through.
Remove shrimp from pan and set aside; cover with foil to keep warm.
Add tomatoes to pan and pour in cream; bring to a boil.
Boil vigorously over medium-high heat, uncovered and stirring often, until sauce is thick enough to coat the back of a spoon; this will take about 8 to 10 minutes.
Return shrimp to pan and stir constantly until shrimp are warmed through, about one more minute.
Stir in ginger, if using, and sprinkle coriander on shrimp.