Flatbread with hummus and spiced lamb

Name: Flatbread with hummus and spiced lamb
Cuisine: Middle Eastern
Ingredients: 1 large flat focaccia, halved horizontally; 300g hummus; 6 (500g) lamb sausages, skins removed; 150g feta, crumbled; 1 tbs za’atar; 1/3 cup (80ml) extra virgin olive oil; 1 small red onion, cut into thin rings (we used a mandolin); 2 tbs red wine vinegar; 2 green zucchini, cut into matchsticks (we used a julienne peeler); ½ cup flat-leaf parsley; ½ cup mint leaves; Finely grated zest of ½ lemon; Juice of 1/2 lemon