In a medium saucepan, combine rhubarb, sugar, and water.

Bring to a simmer over medium heat, stirring occasionally.

Reduce heat to low and continue to cook for 10–15 minutes, until the rhubarb softens and breaks down.

Stir in vanilla extract, lemon juice, and a pinch of salt. Adjust sugar to taste if needed.

For a smooth sauce, use a blender or immersion blender. For a chunky version, leave as is.

Let cool. Store in a jar or airtight container in the refrigerator for up to 1 week.