Heat a pot with a lid over a medium-high heat with a drizzle of oil and butter. Once hot, add the onions and fry for 5 min. Add the garlic, turmeric, ras el hanout and cumin powder. Fry for 1 min. Add the red lentils, measured water and stock cube. Cover and simmer for 15 min or until the lentils are soft. Add a splash of water if the soup is too thick.