Cut the orange into slices and sprinkle with cloves. Also cut the lemon into slices. Put all ingredients except for the cognac in a saucepan and bring to the boil briefly. Let simmer for about half an hour.
Now add a cup of cognac and simmer again for 15 minutes. To taste.
The lemon could possibly dominate the taste. I solved the problem by adding half an orange.
Now let it steep a little and the warming machine for the winter time is ready.