Chicken Burger with Yoghurt Sauce

Burger

• 30 g bread, torn in pieces
• 1 - 2 sprigs fresh rosemary, leaves only, to taste
• 1 - 2 garlic cloves, to taste
• 500 g chicken breasts, skinless, cut in pieces (2-3 cm)
• 1 large egg
• ½ tsp fine sea salt
• 1 - 2 pinches ground black pepper, to taste

Yoghurt Sauce

• 125 g plain yoghurt
• 5 fresh chives, finely snipped (2 mm)
• 1 Tbsp lemon juice
• ½ tsp grated lemon zest (optional)