Preheat oven to 425 F. Lightly grease a baking dish.
Pat the salmon dry with a paper towel. Mix together the lemon juice, olive oil, garlic, & Dijon mustard in a small bowl. Place the fillets in the baking dish & rub with this mixture. Season with a generous pinch of salt & pepper.
Bake for 10-12 minutes, or until the salmon is cooked through.
Boursin Sauce
As the salmon bakes, melt butter in a small pot over medium heat. Pour the chicken stock into the mixture & blend in the Boursin until it’s thoroughly incorporated with the stock. Allow it to simmer for a few minutes until the sauce begins to thicken. Take off the heat & stir in the lemon juice & any natural pan juices from the salmon.
Serving
Place cooked salmon on a serving plate & pour sauce over top.