2 Tbsp vegetable oil
1-1/2 to 2 Tbsp red curry paste
1 Tbsp shrimp paste
1-1/2 cups unsalted roasted peanuts, finely ground
1/4 cup granulated sugar or palm sugar
2 cups unsweetened coconut milk
2 cups chicken broth
1/2 cup tamarind concentrate*
3 Tbsp hoisin sauce
1/2 cup packed fresh Thai basil leaves, minced
1/2 cup packed fresh cilantro leaves, minced
In a saucepan, heat the oil over medium heat. Add the curry paste and stir-fry until fragrant, about 2 minutes. Add the shrimp paste and continue to stir-fry until the shrimp paste is broekn up and one shade darker, about 1 minute. Add the peanuts and stir, roasting until two shades darker but not burnt, 8-10 minutes. Add the sugar and continue to stir-fry until the sugar is dissolved and starts to caramelize, 1-2 minutes. Add the coconut milk, chicken broth, tamarind concentrate and hoisin sauce. Reduce the heat to low and simmer the sauce until slightly thickened (look for a créme anglaise consistency), about 30 minutes. By that time, the natural oils from the peanuts should have surfaced. Turn off the heat and add the basil and cilantro. Cover and let cool. Store in the refrigerator for up to 3 days.
*TO MAKE TAMARIND CONCENTRATE: Place a 16-oz package of tamarind pulp in a bowl and pour 2 cups of boiling water over it. Cover with a plate and allow the pulp to steam and soften for 30 minutes. With a fork, loosen the pulp in the hot water until thick and cloudy. Strain through a sieve set over a bowl, pressing on the pulp with the back of a large spoon. Discard the seeds and fibers. Transfer the concentrate to a jar. Cover and refrigerate for up to 1 week, or freeze in an ice cube tray for up to 3 months.