Spinach& Lentil Soup

• 2 potatoes
• 1 1/2 lentils
• 1 onion
• 1 garlic clove
• 2,400 ml water
• 60 ml lemon juice
• 60 ml olive oil
• 38 gr spinach
• 8 gr salt
• 2 gr coriander black pepper pitas (cut into wedges)