I usually double this recipe, as a large bag of carrots yields lots of salad.
Using tamarind is the traditional method; however it is hard to find in regular grocery stores. Any Asian grocery store/market will have it. Lime juice makes a reasonably good substitution.
The amounts of Thai red curry paste and red pepper flakes can be increased to suit your taste (it is Thai food after all).
The dressing is very similar to one of the dipping sauces usually served with Thai spring rolls, so the dressing can be made on its own for that purpose. I have also used this as a dressing for a thin sliced cabbage slaw.