Redibase Beef And Barley Soup

• 3 potatoes
• 2 onions (chopped)
• 2 garlic (cloves finely chopped)
• 2 carrots (sliced)
• 1/4 barley
• 1,200 ml water
• 475 gr stewed tomatoes
• 450 gr beef chuck
• 240 gr peas (frozen)
• 45 gr mushrooms (sliced)