Chop 4 rashers of bacon. Heat oil and butter and cook onions and bacon until onions are soft and bacon is not quite cooked.

Add the pumpkin, potato, lentils, stock and thyme and season with pepper. Do not add salt yet - you may not need it. Cover and simmer gently for 30 minutes.

Purée with a hand blender or food processor until fairly smooth.

Meanwhile, grill the rest of the bacon until crisp and break in to small pieces. Stir the creme fraiche in to the soup and re-heat, taking care not to boil.

Serve sprinkled with bacon. For a veggie alternate, leave out bacon and serve sprinkled with roasted pumpkin seeds.