Heat oil in a saucepan, fry garlic until golden-brown, then add chili, passata, and salt.
Simmer the tomato sauce gently for 4-5 hours.
Blend mustard fruits and 30g of syrup in a blender until smooth.
Preheat oven to 160°C.
Rub pumpkin wedges with oil and salt, then bake on a tray for 20 minutes.
Peel and discard the skin from the cooled pumpkin wedges.
Sauté shallots, chili, and garlic in oil, then add cavolo nero, 4 tablespoons of water, and salt.
Cover and cook cavolo nero over medium heat for 20-25 minutes until soft.
Reheat pumpkin in the oven, then top with mustard fruit purée, lemon zest, and Parmesan.
Bake briefly until the cheese softens and begins to melt.
Fry sage leaves in a small amount of hot oil until crisp and drain on paper.
Plate the cavolo nero, add tomato sauce, then place the pumpkin on top.
Garnish with two crushed amaretti biscuits per serving and the fried sage leaves.