In 3-quart saucepan heat cranberries sugar vinegar and water to boiling over high heat stirring frequently
Reduce heat to low simmer uncovered until most of cranberries pop about 10 minutes
Add diced pear cover and cook about 10 minutes longer Cover and refrigerate relish until well chilled about 4 hours Can be transferred to an airtight container and kept in refrigerator for up to 2 days