When three members of my extended family went vegetarian, my burger-grilling game suffered. I did what any well-intentioned but misguided carnivore would do: I bought some frozen veggie burgers and called it a day. Since then I’ve upped my veggie burger game, although the simplest veggie burger of all remains a family favorite: the giant portobello mushroom cap. Bonus: This dish is low-calorie, leaving wiggle room for cheese, sauce and a bun.

• 4 large portobello mushroom caps, gills removed
• 1 tablespoon balsamic vinegar
• Olive oil spray
• Salt and pepper, to taste
• 4 slices Gouda or other melting cheese
• 4 whole-grain hamburger buns
• 1 cup peppery greens, such as arugula or a mix
• 4 large slices of tomato, or 8 small slices
• 12 baked tortilla chips
• >> Sauce:
• 1/3 cup low-fat Greek yogurt
• 3 tablespoons low-fat mayonnaise
• 3 tablespoons roughly chopped fresh cilantro
• 1 scallion, roughly chopped
• 1 garlic clove, roughly chopped
• 1 teaspoon Worcestershire or soy sauce
• 2 tablespoons lemon juice
• 1 tablespoon water, if needed
• Pepper, to taste

Blend sauce ingredients until mixed, but with small flecks of green. Pour into bowl and chill, up to 3 days.

Heat grill to medium high. Brush mushroom caps with balsamic vinegar, spray liberally with olive oil, and season with salt and pepper. Grill 3 minutes on smooth side, then flip. Top with cheese and grill, covered, another 3 minutes, until mushroom is tender and cheese is melted.

Meanwhile, toast buns 1-2 minutes on cut side. Place greens on bottom of bun, then tomato. Place mushroom caps on tomato. Top with sauce, then 3 chips, then cover with top bun. Serves 4.

Approximate nutritional information, per serving: 357 calories, 15 g fat, 5 g saturated fat, 23 mg cholesterol, 626 mg sodium, 45 g carbohydrate, 8 g fiber, 9 g sugar, 15 g protein