Heat 1 Tbsp of olive oil in a hot frypan, add garlic and diced onion. Cook for a minute, add the mince and cook until browned. Add tomato paste, followed by Worcestershire sauce and diced tomatoes. Stir after each addition. Add the beef stock slowly and bring to boil, reduce heat and simmer uncovered for 20min.
While mince is simmering cut eggplant into rounds, heat frypan with 1 tbsp olive oil and add eggplant pieces in batches and cook for 2-3min each side (you still want it fairly firm). Lay grilled eggplant on paper towel and put aside.
To make your white sauce: gently heat 2 Tbsp of butter in a small saucepan, on low heat. Remove from heat and add plain flour, salt and pepper. Gradually add milk, continuing to mix, to make a smooth sauce. Put saucepan back on the heat and mix until sauce boils and thickens. Mix in a small handful of cheddar cheese.
To assemble the lasagna: add half the mince mixture, followed by pieces of fried eggplant; pour over half the white sauce and sprinkle with cheddar cheese. Place a layer of lasagna sheets, breaking sheets to get into corners of dish if necessary. Repeat with remaining mixture, finishing with another layer of pasta sheeting, white sauce and cheese.
Cover with lid and cook in oven for 30min. Remove lid and cook for another 15min, or until cheese is browned and the lasagna sheets are soft when tested with a knife.