In large heavy saucepan, combine all ingredients over medium heat, stirring to combine. Continue to barely simmer uncovered, stirring occasionally for 30 minutes, until texture is thick and aroma complex. Taste and adjust flavor accordingly. Add sugar for sweetness, maple balsamic to deepen colour/flavour/acidity, cinnamon and/or nutmeg for warmth, or salt for balance.
Allow to cool to room temperature. Transfer to storage container up to two weeks in refrigerator or up to a month in freezer.