Combine everything except the chicken and whisk until well mixed. Add chicken and coat throughly. Cover and chill 2-4 hours or overnight. Stir once in a while. Grill over medium to hot oiled grill 5-7 min on each side until chicken is white in the center. Serve with beans and rice. About 4 servings.

Notes:
Sour oranges are also called Seville orange; the orange/grapefruit mixture below is a pretty good duplicate. I used 2 Tbs of habanero paste and it went very well with a rice/bean mixture I threw together -- spicy enough to need the blander rice and beans. I broiled the chicken since it was raining rather heavily at the time ;-)

From: Global Grilling', by Jay Solomon
Posted By: mike, mikeb@radonc.ucdmc.ucdavis.edu, Via: Chile Head Mailing List
Post Date: Sunday, December 12, 1999