Rinse the cranberries under cold water. Pick out any soft or shriveled ones. Peel and dice the Granny Smith apple into small, even pieces. Zest and juice the orange and lemon. Set everything aside and ready to go.

Add the cranberries, sugar, and one cup of water to your saucepan. Place over low to medium heat. Stir gently to combine. Let everything heat up slowly together.

Cook for about 5 minutes over low heat. You will hear and see the cranberry skins begin to pop open. Do not walk away. Watch the pot and stir occasionally to prevent sticking.

Once the berries have popped, add the diced apple, orange zest, lemon zest, orange juice, and lemon juice. Stir everything together gently. The sauce will start to smell incredible at this point.

Continue cooking on low heat for another 15 minutes. Stir occasionally. The apple will soften and the sauce will thicken. Taste and adjust sweetness if you like.

Remove from the heat. Let the sauce cool completely at room temperature. Then transfer it to an airtight container and refrigerate. Serve chilled. The sauce thickens even more as it cools.