Steps
1. Heat olive oil in a small saucepan over medium heat.
2. Add chopped onions and sauté until soft and translucent, about 5 minutes.
3. Add mustard seeds and cook until they start to pop.
4. Stir in chopped green plums, cranberries, brown sugar, apple cider vinegar, cinnamon, cloves, ground ginger, chili (if using), and salt.
5. Bring the mixture to a boil, then reduce heat to low and simmer uncovered for 30-40 minutes, stirring occasionally, until the chutney thickens.
6. Remove from heat and allow cloves and chili to infuse for 10 minutes, then remove them.
7. Allow chutney to cool before serving or storing in a sterilized jar.