Combine ingredients in a 2 to 4-quart sauce pan. Bring to a boil, then reduce heat to medium. Cook, uncovered, until liquid is gone and mixture is very thick, 40-50 minutes, stirring occasionally. Reduce heat if needed the last 10 minutes.

Remove pan from heat and cool, uncovered, 15 minutes. Transfer to a food processor and blend until smooth. Refrigerate until ready to use. Spread may be stored in the fridge up to 1 week.