Put the dried shrimp (if using) in a small bowl, pour over boiling water and soak for 10 minutes.
Use a julienne peeler to shred the mango flesh from the large seed and the carrot into long thin threads. Chop the shallot into thin rings. Tumble together into a large bowl.
For the dressing, heat the vegetable oil in a frying pan, then add the garlic and very gently sizzle over a low heat for 3–4 minutes until it just takes on a little colour. Next, add the drained shrimp and chopped chilli. Sizzle for another 1 minute.
Now, add the sugar, 1 teaspoon of salt and the warm water, mixing until the sugar and salt dissolve. Remove from the heat, then whisk through the tamarind paste, lime zest and juice, and fish sauce. Pour into a bowl and leave to cool completely.
Once cool, whisk the dressing one last time, then pour over the shredded mango and carrots, tossing to coat everything well. Tear in the fresh mint, mixing again, then garnish with roasted cashews and crispy onions.
