In a small saucepan over medium-low heat, gently bring the oil and garlic to a boil. Reduce the heat to the lowest setting and simmer very gently until tender, about 15 minutes. Set aside.
Preheat the grill, setting the burners to medium.
In a glass baking dish, combine 30 ml (2 tablespoons) balsamic vinegar and 30 ml (2 tablespoons) garlic oil. Add the steak and coat well. Set aside.
Place the vegetables on a baking sheet and coat with 60 ml (1/4 cup) garlic oil. Season with salt and pepper.
Grill the vegetables until tender, about 4 to 5 minutes, depending on their size. Transfer the vegetables to a large bowl. Add the remaining oil, vinegar, garlic and prosciutto. Toss. Adjust the seasoning. Set aside.
Set the grill to high.
Grill the steaks for 2 to 4 minutes per side or to desired doneness. Flank steak is best eaten rare.
Serve the steak with the warm grilled vegetable salad. Garnish with basil leaves.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.