In a medium saucepot, add chopped rhubarb, about 1 cup of sugar (or 200 grams), and an equal amount of water. Bring it up to a medium heat until it begins to boil.
Once boiling, reduce to a simmer and simmer for about 5 minutes, stirring continuously.
After 5 minutes, the cooked rhubarb should be broken down and the contents of the pot should be pink. All sugar should be dissolved.
Place a large bowl or container in the sink with a fine-mesh strainer on top of it. Pour the contents of the pot into the strainer. Use rubber spatula to press out all of the syrup into the bowl. Either discard the cooked rhubarb parts or save for another use.
Allow syrup to cool completely in a bowl. Then store or use immediately.