In a large non-stick frying pan heat half the oil over medium-high heat. Cook mince in batches until browned. Set aside on a plate.
Heat remaining oil in same pan over medium-high heat and cook onion, garlic, carrot and eggplant for 5 minutes or until softened.
Return beef to pan, add thyme, tomato paste, tomatoes, Worcestershire and stock. Bring to the boil, reduce heat and simmer over medium-low heat for 20 to 25 minutes or until sauce has thickened. Remove from heat and stir through spinach. Season to taste and set aside.
Meanwhile, in separate microwave safe containers microwave cauliflower (4 to 5 minutes) and peas (2 to 3 minutes) on HIGH (100%) until tender. Drain. Roughly mash with milk, mustard and cheddar. Season.
Lightly oil a 2-L (8-cup) capacity baking dish, add beef mixture and top with spoonfuls of cauliflower mash. Sprinkle with parmesan. Bake for 20 to 25 minutes or until golden and bubbling. Set aside to cool for 5 minutes. Serve with extra baby spinach leaves.