Put a pot of water on the heat for the pasta. Mix together the garlic, harissa, tomato puree, cumin and lemon juice and set aside. Heat an inch of olive oil in a wide skillet over a high heat and fry the sliced aubergine in batches until golden on both sides adding more oil as needed. Place the fried aubergine on a paper towel lined plate and season with plenty of salt.
While the aubergine is frying cook the pasta according to packet instructions. Reserve a mugful of pasta water before draining.
Once all the aubergine has been fried turn the heat down and add the harissa mixture. Add the pasta and the pasta water a tablespoon at a time tossing until the sauce coats the pasta. Return the aubergine to the skillet and toss again. Remove from the heat and serve topped with feta and dill.
Nutrition information is an estimate and will vary depending on the exact ingredients used.