Peel the vegetables. Cut finely potatoes and carrots into pieces, chop leeks into thin circles (set aside a half).Heat the oil in the thick pan and fry vegetables until golden brown. Pour over the broth, bring to a boil, season with bouillon powder, boil for about 25 minutes until vegetables become soft. Add processed cheese and melt. Blend the soup, add the remaining leeks, heat, season with salt, pepper and nutmeg, serve.