Soak the chickpeas in plenty of cold water overnight.
Drain and rinse the chickpeas.
Place the chickpeas in a medium saucepan with 3 cups of cold water.
Bring the chickpeas to the boil over a high heat using either a stove top, or your barbecue side burner (if applicable). Once boiling, reduce heat so the chickpeas are simmering. Cook the chickpeas for 1 ½ hours or until tender. Keep an eye on the water level. If it gets too low add more hot water to the pan.
Once the chickpeas are cooked drain them and rinse them with cold water. Set aside until needed.
Rinse the lentils in cold water and check there are no small stones.
Place the lentils in medium saucepan with two cups of cold water.
Bring to the boil and cook for 20-25 minutes or until tender. Drain and rinse with cold water. Set aside until needed.
Rinse the quinoa in cold water. Place in a small saucepan with one cup of cold water. Bring to the boil then reduce the heat to low. Cook for 15 minutes or until all the water has been absorbed. Set aside to cool, then fluff with a fork.
Bring one cup of water to the boil in a small saucepan. Add the buckwheat to the boiling water. Reduce the heat to low and cook the buckwheat for around 10 minutes or until all the water has been absorbed. Set aside to cool then fluff with a fork.
To make the dressing place the oil, lemon juice and salt in a small screw top jar. Shake until well combined.
In a large bowl place the chickpeas, lentils, quinoa, buckwheat, tomatoes, parsley, mint and onions. Top with the dressing and mix through.
Preheat your barbecue for direct cooking for 10 minutes. Please refer to the handbook included with your barbecue for settings.
Remove the lamb from the fridge and rub with the lemon juice, oil, garlic, thyme leaves, salt and pepper.
Once your barbecue is preheated, leave on the direct cooking settings.
Cook the lamb for 7-10 minutes a side depending on how well done you like your lamb cooked. (7 minutes a side for rare, 10 minutes a side for well done.)
After resting for 5-7 minute, carve and serve with the salad.