Place Red Apple (3), Pear (3), Cinnamon Stick (2), Lemon (1 tablespoon), Ground Nutmeg (1/2 teaspoon), Caster Sugar (to taste), and Water (1/4 cup) in a large pot and bring to a boil. Reduce the heat to medium-low and cover for about 30 minutes. Make sure to keep an eye on the sauce and to stir frequently. The apples should be soft and golden when finished.
Taste and add more sugar if needed.
Remove cinnamon sticks.
For a smooth sauce, beat with a whisk or run through a foodmill. Sprinkle with some ground cinnamon before serving.