Combine dried red chiles, garlic cloves, shallots, lemongrass stalk, and ground turmeric in a food processor.

Grind the ingredients until fairly smooth, scraping down the sides of the machine as needed.

Heat peanut oil in a saucepan over medium heat.

Sauté the chile-garlic mixture until fragrant, about 1 minute.

Add coconut milk, palm sugar, nam pla, lime juice, and salt to the saucepan.

Whisk until the sauce is smooth.

Simmer the sauce until it thickens, about 15 minutes.

Store the peanut sauce, covered and refrigerated, for up to a week.

Gently rewarm over very low heat or in a microwave before using.