Cook lentils in water with stock cubes and 1 ½ tsp BBQ Blokes Spice until water has evaporated entirely. The lentils should have a slight crunch, so not quite al dente. Take care not no burn when the water disappears.
Whilst the lentils are cooking, preheat the oven to 180°C. Cut the sweet potatoes into 1.5cm slices, transfer to a bowl and toss in generous amount of olive oil. Add 3 teaspoon BBQ Blokes Spice and toss again, so that the sweet potatoes are coated. Transfer to baking dish and cook in the oven until brown and soft. Turn once in between and drizzle with more oil if necessary.
Once the lentils are cooked, take off the heat for 5 minutes, then add cinnamon, cardamom, garlic and lemon zest to the pot and stir.
When the sweet potatoes are cooked, chop up coarsely and add to pot of lentils. Smash everything together with a pestle until you have a dip-like consistency.
Lift under barberries, thyme, half of lemon juice and 3 heaped tablespoon Greek yoghurt. Season with salt and pepper to taste. Carefully lift under fresh herbs.
Serve with a big dollop of yoghurt, a sprinkle of barberries, the remaining lemon juice and a generous drizzle of olive oil.