Pour the beef broth into a wide, deep skillet. Bring it to a strong boil over high heat, then let it cook down until you have about 1 cup left. This should take around 15 to 20 minutes. Set it aside.

Over a gas flame or in a dry skillet on high heat, char the onion and ginger until they’re nicely blackened around the edges. Remove the ginger first, then smear the shrimp paste onto the onion. Pop it back onto the heat for about 30 seconds until it’s blistered.

In a small dry skillet, toast the star anise, cloves, and peppercorns over medium-low heat until fragrant. Take them off the heat, then add the ground fennel, coriander, cinnamon, and white pepper, stirring briefly.

Transfer everything—the charred onion and ginger along with the toasted spices—into a blender. Add lemongrass, fish sauce, brown sugar, and MSG (if using), along with the reduced broth. Blend on high for about 2 minutes until the mixture is completely smooth.

Pour your concentrate into an airtight container and refrigerate it for up to a month. Shake or stir well before each use. You can freeze it in small portions for easy access later.

When you’re ready to enjoy, heat up 2 cups of beef broth and mix in 3 1/2 tablespoons of your concentrate. Allow it to gently simmer for about two minutes. Strain the broth to keep it perfectly clear and then taste it—add a splash of fish sauce if desired.

Once it’s just right, place cooked rice vermicelli in a bowl, pour the hot broth over it, and top it with your beef or meatballs. Garnish with fresh slices of onion, scallions, crunchy bean sprouts, and fragrant Thai basil. Serve with citrus wedges and chili sauce for a truly satisfying experience!