Rosemary Flank Steak with Roasted Potatoes

6 tablespoons canola oil
3 medium Spanish onions—1 thinly sliced, 2 cut into thin wedges attached at the root end
3 garlic cloves, thinly sliced
2 shallots, thinly sliced
1/3 cup minced fresh rosemary
2 tablespoons red wine vinegar
1 teaspoon ground cumin
1/2 teaspoon cayenne pepper
1 3/4 pounds trimmed flank steak
2 pounds small unpeeled new potatoes, quartered
2 tablespoons balsamic vinegar
1 tablespoon olive oil
Salt and freshly ground pepper

Heat the canola oil in a large nonreactive skillet. Add the sliced onion, garlic and shallots and cook over moderately low heat, stirring, until softened, about 5 minutes. Add the rosemary and cook for 1 minute. Add the red wine vinegar, cumin and cayenne pepper and let cool.
Scrape the marinade into a large, sturdy resealable plastic bag. Add the flank steak and spread the marinade over it. Seal the bag and refrigerate for 1 to 4 hours, turning the bag twice.
Preheat the oven to 400°. In a large bowl, gently toss the potatoes, onion wedges, balsamic vinegar and olive oil and season lightly with salt and pepper. Spread the vegetables in a large nonstick roasting pan and roast for about 40 minutes, stirring once, until tender and browned.
Light a grill or heat a large cast-iron grill pan. Scrape the marinade off the steak. Grill the steak over moderately high heat for about 15 minutes, turning once, until browned and medium-rare. Cover with foil and let rest for 5 minutes. Season the meat with salt and pepper. Thinly slice the steak across the grain and serve with the roast potatoes and onion wedges.

Notes One Serving Calories 348 kcal, Protein 24 gm, Carbohydrate 30 gm, Cholesterol 50 mg, Total Fat 14.6 gm, Saturated Fat 3.8 gm.