Remove from heat and carefully pour in vinegar. (Stand back, as caramel may sputter slightly.) Add fruit, serranos (or jalapenos), ginger, salt and the reserved ground coriander. Return saucepan to medium-high heat and bring to a simmer, stirring occasionally. Reduce heat to low and simmer, stirring occasionally, until the fruit is tender and the chutney has thickened, 3 to 5 minutes. Let cool.