Place jalapeño and poblano on a foil-lined baking sheet; broil 10 minutes or until blackened, turning occasionally. Place in a zip-top plastic bag; seal. Let stand 15 minutes. Peel jalapeño and poblano; cut in half lengthwise. Discard seeds and membranes; coarsely chop.
Heat oil in a large saucepan over medium-high heat. Add onion, ginger, and garlic; sauté 5 minutes or until tender. Add jalapeño, poblano, plums, and next 6 ingredients (plums through black pepper); bring to a boil. Cover, reduce heat, and simmer 30 minutes, stirring occasionally. Uncover and simmer an additional 15 minutes or until liquid almost evaporates, stirring occasionally. Cool completely. Stir in cilantro.