I have the Seville Oranges and a bottle of vodka lurking in the cupboard and this will not be a time consuming exercise but should make a liqueur type drink for special occasions. Something for Christmas 2015. It only uses the peel from the oranges therefore with little extra vodka some Rose wine, red wine or white wine you can make Vin d'orange at the same time so as not to waste the oranges.
Peels of 6 Seville Oranges
6 fresh rinsed leaves if available (optional)
1 1/2 cups sugar dissolved in 1 cup of hot water (stir over flame and do not let it carmelise)
1 bottle of cheap vodka
Allow the sugar syrup to cool.
Place the thinly sliced peels and leaves into a wide mouthed jar, pour in the syrup and top up with the vodka. Cheap vodka works best because the more expensive stuff has its own flavour and aroma which you do not want interfering with the Liqueur.
After four weeks, taste it to see if you need to adjust the sweetness. If it does require extra sweetening make up the syrup as before, adding a little each day until you happy with the sweetness and letting the syrup mix in and dissolve. Do not make any more syrup as this will weaken the alcohol content and each person's palate on sweetness differs so much. Decant and filter into nice bottle(s) and keep somewhere nice and cool to bring out on special occasions.