Easy beef stew

Name: Easy beef stew
Prep time: 20 min
Cook time: 2 h 15 min
Total time: 2 h 35 min
Cuisine: European, British
Ingredients: 350g stewing beef; 2 tbsp plain flour seasoned with black pepper; 3 tbsp olive oil; 2 onions, peeled and finely chopped; 2 cloves garlic, peeled and finely chopped; 4 carrots, peeled and cut into chunks; 300ml stock; 400g tin chopped tomatoes; 2 tsp English mustard