1. In a non-aluminum saucepan, combine sugar and rhubarb. Let stand at room temperature until the rhubarb begins to release its juices, about 15 minutes.
2. Add cinnamon and cloves. If the rhubarb hasn't released much juice, add water a tablespoon at a time just until the bottom of the pan has a coat of water. Bring to a boil, stirring constantly.
3. Let boil a few minutes. Then, reduce heat, cover and simmer until rhubarb is tender and liquid thickens, about 10 to 12 minutes. Stir mixture occasionally. Taste, adding more sugar if needed.
4. Remove saucepan from heat. Let cool to room temperature without stirring. Rhubarb will thicken as it cools.
5. If you want a thicker sauce, refrigerate for at least 2 hours.
6. Serving suggestions: Spoon over vanilla ice cream or Greek yogurt. Use as a sweet and tangy sauce or glaze for chicken, pork, ribs or tofu.