Preheat the oven at 180C

In a bowl toss eggplant, red capsicum, onion, salt, red chilli powder, garlic and thyme. Drizzle the olive oil and toss to coat thoroughly. Spread in one layer on a baking sheet. Bake for 40 to 45 minutes, until vegetables are soft and lightly browned. Remove from oven. 

Put the roasted vegetables in a blender or food processor. Add tomato paste and lemon juice. Pulse until pureed. Taste and adjust seasoning. Serve with pita chips or nachos.