Preheat the oven to 180c regular bake.
Heat oil in a large frying pan, add chicken, brown on each side, transfer to a roasting dish with pumpkin, season with salt and pepper, bake for 20-25 minutes, mash the pumpkin and shred the chicken.
Cook onion in the same pan, add garlic, wine, tomato paste, stock, tomatoes, herbs, balsamic, simmer for 20 minutes, add spinach and shredded chicken.
Make a cheesy white sauce: Melt butter, add flour, stir in milk, cook until thickened, stir through cheese, season.
Grease a baking dish, layer tomato mixture, cheese sauce, lasagna sheets, mashed pumpkin, repeat layers, top with white sauce and extra cheese.
Cover with foil, bake for 35 minutes, remove foil, grill until golden brown, rest for 10 minutes before serving.
