Combine water, raw sugar, and honey in a medium sauce pan.
Simmer the mixture over medium heat for 20-30 minutes, stirring occasionally to evenly combine the ingredients. You’ll want to keep an eye on the pot as it can start to bubble over if the heat is too high or left unattended too long. You will know it’s ready when all the sugar and honey has dissolved, the mixture has thickened slightly, and it has reduced by ⅓ to ½ of the original amount. It should have a translucent rich caramel color.
While this is simmering, wash the orange well and slice it into segments. Reserve a quarter of the orange slices to be used as garnishes.
Reduce heat to medium low, and add the remaining three quarters of the orange slices and the sage leaves to the syrup. Allow to simmer, not boil, for 40 minutes to 1 hour. The oranges will release more liquid into the pot, thinning out the syrup you just made; the goal is to reduce the mixture again until it’s thick and tastes of oranges and sage.
Once reduced to your preferred consistency and flavor, strain the mixture into a measuring cup, pressing the fruit slices to get as much syrup out of them as possible. Allow the syrup to cool before transferring it into a sterilized jar for storage. Discard the oranges and sage leaves. The syrup is best used when cold, and can be made ahead of time and kept in the refrigerator until needed. Leftover syrup will keep 3-4 weeks in the fridge.