Veggie Cheeseburgers

Ingredients

• Lemon Mayonnaise

  • 1/3 cup (75 ml) mayonnaise
  • 1/3 cup (75 ml) plain Greek yogurt
  • 1/2 lemon, the grated zest only
  • 1 tbsp chopped fresh chives

• Burgers

  • 1 small red onion, sliced
  • 1 tsp sugar
  • 1 tsp salt
  • 1 eggplant, cut into slices 1/2 inch (1 cm) thick (about 8 slices)
  • 1/4 cup (60 ml) olive oil
  • 1 zucchini, cut into slices 1/4 inch (5 mm) thick
  • 3/4 lb (340 g) halloumi-style grilling cheese, cut into four slices 1/2 inch (1 cm) thick
  • 4 hamburger buns, lightly toasted
  • 4 Boston lettuce leaves
  • 1 tomato, sliced