1. Preparation
Gather all ingredients and ensure you have a clean workspace.
Peel and chop the potatoes into bite-sized cubes.
Dice the onion and chop the garlic and ginger finely.
Cut the beef into 1-inch cubes, trimming excess fat if necessary.
Measure out the spices and coconut milk.
2. Make the Massaman Curry Paste
In a small bowl, combine the ground cinnamon, cumin, coriander, cardamom, cloves, and nutmeg to create the spice mix.
If using whole spices, lightly toast them in a dry pan for 2-3 minutes until fragrant, then grind them into a powder.
In a mortar and pestle or food processor, blend the garlic, ginger, chili paste (or fresh chilies), and a bit of water until it becomes a smooth paste.
Add the prepared spice mix to the paste and blend until combined.
3. Cooking
In a large pot or Dutch oven, heat the vegetable oil over medium heat.
Add the diced onion and sauté for about 5 minutes until translucent.
Stir in the Massaman curry paste and cook for an additional 2-3 minutes until fragrant.
Add the beef cubes to the pot, stirring to coat them in the paste. Cook for 5-7 minutes until browned on all sides.
Pour in the coconut milk and add enough water to ensure the beef is submerged.
Add the chopped potatoes, tamarind paste, and sugar. Season with fish sauce to taste.
Bring the mixture to a simmer, then reduce the heat to low. Cover and let it cook for about 30-40 minutes, stirring occasionally, until the beef and potatoes are tender.
Adjust seasoning with additional fish sauce or sugar if needed before serving.
4. Serving
Serve the Massaman curry hot over steamed jasmine rice.
Garnish with chopped peanuts and fresh cilantro, if desired.