Heat 1 tablespoon of oil in a large saucepan/wok and fry the bacon until browned.
Remove with a slotted spoon and reserve.
Add diced onion to pan and gently fry over low heat to soften. Reserve with bacon.
Over medium heat, add the remaining 2 tablespoons of oil, chopped carrots, parsnip, and leeks, and stir for 2 minutes.
Return the bacon and onion to the pan and add the red lentils.
Stir in tomato puree (paste) and stock.
Bring to a boil, then simmer covered for 25 minutes or until the red lentils and vegetables are tender.
Stir in orange juice, salt, and pepper. Taste and adjust seasoning if necessary.
Ladle the soup into bowls and garnish with grated Cheddar cheese and chopped parsley. Then serve with crusty bread.