Place all the ingredients in a blender or small food processor & blend or process until smooth.
Place tamarind pulp in a small heatproof bowl. Cover with boiling water & let sit for 5 to 10 minutes to soften. Drain the mixture through a fine sieve into a small bowl, pressing the pulp to extract the flavor. Discard the pulp but keep the liquid.
In a large saucepan or medium sized pot, combine curry paste, beef, remaining coconut milk, broth, star anise, palm sugar, dish sauce & tamarind liquid. Bring to a boil then reduce the heat to low. Simmer, covered, for 1 1/2 hours or until the beef is tender.
Add the potatoes. Increase the heat to medium-low. Cook, uncovered, stirring gently occasionally, for 30 minutes or until the potatoes are tender but not falling apart & sauce is thickened. Serve with rice & extra peanuts.