Thai Massaman Curry Paste

https://www.seriouseats.com/prik-gaeng-massaman-thai-massaman-curry-paste-5190555

INGREDIENTS

• 5 Thai or Chinese white cardamom pods (see note)
• 1 cinnamon stick, broken into pieces
• 1 piece whole nutmeg, broken into pieces
• 10 whole cloves
• 6 blades mace
• 2 teaspoons coriander seeds
• 1 teaspoon whole cumin seeds
• 1 teaspoon white peppercorns
• 10 dried spur chiles (15g), stemmed and seeded (see note)
• 2 stalks lemongrass, bottom 4 to 5 inches only, outer leaves discarded, tender core thinly sliced (about 20g sliced lemongrass)
• 4 small shallots (75g), thinly sliced
• 7 small garlic cloves (25g), thinly sliced
• 3 coriander roots (10g), cleaned and thinly sliced (see note)
• 1 ½ teaspoons (15g) Thai shrimp paste
• 1 teaspoon (4g) Diamond Crystal kosher salt

DIRECTIONS

1. Place cardamom, cinnamon, and nutmeg in a medium nonstick skillet and set over medium-low heat. Cook, tossing frequently, until fragrant, about 5 minutes. Add cloves, mace, coriander seeds, cumin, and white peppercorns, and continue to cook, tossing frequently, until spices are fragrant and darkened in spots, 4 to 5 minutes longer. Remove from heat and allow to cool slightly. Transfer to a spice grinder and grind into a fine powder. Transfer mixture to a small bowl, and set aside.

2. Add spur chiles to now-empty skillet and toast over medium-low heat until fragrant and charred in spots, 2 to 3 minutes. Set aside to cool for 2 minutes, then transfer to spice grinder and grind into a fine powder. Set aside.

3. Add lemongrass to skillet and cook over medium heat, stirring frequently, until dry and lightly  charred at edges, about 5 minutes. Transfer to a plate or rimmed baking sheet and set aside. Add shallots to skillet and cook over medium-low heat, stirring frequently, until shallots just begin to shrivel and char at edges, 2 to 3 minutes. Add coriander root and garlic, and continue to cook, stirring frequently, until  lightly charred at edges, about 3 minutes. Transfer to plate with lemongrass, and set aside to cool.

4. Spread shrimp paste evenly in the center of a 10- by 6-inch piece of foil (or a 10- by 6-inch piece of banana leaf). Close foil to form a flat packet, add to now-empty skillet, and toast over medium-low heat, turning occasionally, until fragrant, about 5 minutes. Remove from heat and set aside.

5. Combine toasted lemongrass, shallots, coriander root, and garlic with salt in a granite mortar and pestle. Pound until a coarse paste forms, 2 to 3 minutes. Pounding thoroughly between each addition to break down and incorporate ingredients into the paste, add ground spur chiles, toasted shrimp paste, and ground spice mixture until a very fine, dry, sticky paste forms, about 10 minutes longer. While pounding, use a spoon to occasionally flip the paste over in the mortar to ensure a consistent final texture. Use right away or transfer curry paste to an airtight container, covering paste with plastic wrap pressed directly onto its surface to prevent it from drying out.