Terrific Tomato Soup with Saffron

Ingredients

• 2 cans of crushed tomatoes
• 1 yellow onion
• 1 carrot
• 10 centimeters of leek
• 2 cloves of garlic
• 1/4 gram of saffron
• 1 tablespoon of white wine vinegar
• 3 deciliters of water (increase if you want a thinner soup)
• 2 deciliters of low-fat cream
• 2 tbs of margarine or butter
• 1-2 vegetable stock cubes
• Some chili flakes
• Black pepper to taste