Melt the butter in a heavy-bottomed pan and add the cumin seeds. Cook gently for 2 minutes until you begin to smell the cumin. Add the diced onion and then cook for a further 2 minutes until its softened and slightly caramelised.
Add the diced butternut and again cook for another 2 minutes. Add the stock or water and bring to a gentle simmer. Cook for approximately 10-15 minutes until the squash is soft and tender. Then add the cream, bring back to a simmer, and remove from the heat.
Blend the mixture in a food processor until a smooth, velvety consistency is achieved. Season with salt and pepper and set aside.
For the Scotch eggs, bring a pan of water to the boil and prepare a bowl of iced water. Drop the eggs into the pan and simmer them for exactly 2 ½ minutes, then put them straight into the iced water to stop the cooking process. Once cold, carefully peel the shell from the eggs and set aside.
Put the flour, beaten egg and breadcrumbs each in separate bowls.
Mix the sausage meat with the thyme leaves, then roll it out between 2 sheets of lightly oiled greaseproof paper to a thickness of 3-5mm. Cut the meat into 4 and place an egg in the centre of each piece. Gently fold the sausage meat around the egg until totally covered.
Roll the Scotch eggs first in the flour, then the beaten egg and finally the breadcrumbs to coat them evenly all over.
When almost ready to serve, heat the vegetable oil to 190C, and deep fry the eggs for 2-3 minutes, until golden and crisp, then drain on kitchen towel.
To serve, pan fry the mushrooms in a little rapeseed oil until tender and gently reheat the soup if needed.
Pour the soup into serving bowls and gently slice the Scotch eggs in half before placing on top, cut side up. Scatter over the mushrooms, seeds and lemon thyme leaves, and serve.