- Preheat oven to 180°C (350°F).
- Cook carrots in a saucepan of boiling water for 4 minutes. Add broccoli and continue cooking for 2 minutes. Add zucchini and cook for an additional 2 minutes. Drain and reserve. Heat vol-au-vent shells in the oven for 5 minutes, or until hot.
- Cook primavera sauce according to manufacturer's instructions. Incorporate yogurt. Add vegetables and shrimp, and gently combine.
- Divide shrimp filling among the four vol-au-vent shells and garnish with fresh lemon balm.
Variation: Replace primavera sauce with a commercial white-wine sauce, omitting yogurt. Add 250 mL (1 cup) mushrooms and 60 mL (1/4 cup) thinly sliced green onion to the mixture, along with 75 mL (1/3 cup) baby scallops.