To make the dressing, combine the vinegar, sugar, mustard, salt and pepper in a bowl. Gradually whisk in the olive oil. Set aside.
In a saucepan, combine the stock, wild rice and butter. Bring to a boil, reduce heat to a simmer and simmer 45 minutes or until stock is absorbed. Let cool to warm.
Heat up a frypan with a little olive oil. Sprinkle the chicken breasts with salt and pepper and saute 8 minutes a side or till done. Let cool slightly and cut into small cubes.
Combine rice, chicken, celery, carrot, almonds and onion in a salad bowl. Add dressing and toss. Serve just warm.