Pair this rich salsa with grilled shrimp, pork, or poultry.
Heat a large skillet over medium-high. Add chiles; cook 90 seconds or until fragrant. Place chiles in a heatproof bowl; add onion. Cover with 3 cups boiling water; let stand 30 minutes. Drain well; place in blender. Add peanuts, sugar, salt, and 1 1/2 cups water; process until smooth, stopping to scrape down sides.