Rinse chicken breasts and pat dry.

Heat vegetable oil in a 10- to 12-inch frying pan over medium-high heat.

Add chicken and cook until browned on both sides (approximately 6 minutes total).

In a small bowl, combine apricot jam and Dijon mustard.

Spread jam mixture over the browned chicken breasts.

Sprinkle frozen blueberries over the chicken.

Reduce heat to medium-low, cover the pan, and simmer until the thickest part of the meat is no longer pink (approximately 15 minutes).

With a slotted spoon, remove chicken and blueberries to a platter and keep warm.

Add white wine vinegar to the pan.

Increase heat and bring the mixture to a boil.

Cook, stirring occasionally, until the sauce has thickened and reduced by 1/3 (approximately 5 minutes).

Pour sauce over chicken and blueberries.

Garnish with watercress or arugula.