Here's the sauce I make when I do duck a l'orange... - this is enough for 3-4 duck breasts.
Â½ tbsp brown sugar
50ml white wine vinegar
250ml orange juice
250ml well flavoured chicken stock
zest of 1 orange, finely sliced
segments from 2 oranges
I pan sear the duck breasts and leave aside to rest after cooking.
To make the sauce, put the sugar and vinegar into a saucepan, bring to the boil and reduce until it begins to caramelise. Add the orange juice, reduce down to one third and add the chicken stock. for the last few minutes I carefully place the segments into the sauce to heat through slightly.
I lay the duckbreasts on a serving dish, carefully place the segments around the duck breasts and then gently pour the sauce over the duckbreasts and segments.