Preheat the oven to 180C. Line a tray with baking paper.
Brush the pita bread with oil and sprinkle with sumac. Place in the oven for 5-8 mins to crisp up. Remove from oven & set aside.
Place the lentils in a saucepan, cover with plenty of water, and bring to a boil. Reduce the heat and simmer for about 20 mins or until tender. Drain, rinse briefly under cold water.
Place the quinoa and 3/4 cup water in a saucepan and bring to a boil. Reduce the heat and simmer for 15 mins or until tender and water absorbed. Remove from heat & place a clean tea towel under the lid to absorb any residual moisture.
For the dressing, combine all ingredients in a small bowl and whisk to combine. Taste and adjust to achieve a balanced dressing.
Place lentils and quinoa into a bowl, add the dressing and toss. Set aside to cool.
To complete the salad, add the red onion, cucumber, tomatoes, herbs and feta cheese and toss gently to combine.
For the spiced chicken: drizzle the chicken with a little oil and sprinkle over the spice mix. Place a frypan over medium-high heat and once hot add the chicken. Cook a few minutes on each side until cooked through. Remove from the pan and set aside to rest.
To serve: spoon some of the lentil salad onto serving plates, break up the pita bread and scatter around, place some pieces of the chicken on top.