A perfect filling sauce for roasted poblano peppers.
Toast peppers on hot skillet, turning to brown evenly. Transfer to a bowl; let cool. Slit peppers open; remove stems and seeds. Reserve peppers; discard stems and seeds.
Place stock and toasted peppers in a small saucepan. Add salt and cumin. Bring to a boil over high heat, reduce to a simmer, and cook 15 minutes until peppers are tender.
Process mixture in a blender until smooth. Reserve until needed. May be made 2 to 3 days ahead and refrigerated. Reheat to serve.