In a medium saucepan over high heat, bring the water and orange juice to a boil. Add in the brown sugar and stir until it is dissolved.
Pour in the cranberries and pear (if using) and stir until the cranberries begin to burst, then lower heat to a simmer, add in the orange zest (if using), and allow to cook for 10 minutes.
Remove from heat and allow to cool to room temperature. Place it in the refrigerator for an hour to chill and continue thickening.
Notes
Too sweet or tart? If it’s too tart, add a little more sweetener (sugar works best, but some more apple or orange juice could also work for natural sweetness). If it’s too sweet, add something acidic, like lemon juice, to cut the sweetness.
Adjust the texture: Based on how chunky you want the pear pieces to be within the orange cranberry sauce. Just note that the smaller the pieces, the less time they’ll take to cook.
For thinner/thicker sauce: Adjust the amount of liquid added for a thinner sauce. To thicken it, add a cornstarch slurry. However, note that the sauce thickens upon cooling. If it’s too thin after chilling, return it to the stove and either simmer to reduce or add starch to thicken.