Butternut Squash & Lentil Stew with Potatoes

Name: Butternut Squash & Lentil Stew with Potatoes
Prep time: 15 min
Cook time: 55 min
Total time: 1 h 10 min
Cuisine: European
Ingredients: 1 tablespoon olive oil; 1 onion, sliced; 1 leek. sliced; 2 large carrots, sliced; 1/2 medium butternut squash, deseeded and peeled, then chopped in small chunks; 4 florets of cauliflower, chopped; 5 baby potatoes (you can use a couple of bigger potatoes), sliced or diced; 235g (8 1/3 oz) green or brown lentils (400g/14oz tin drained); 1 tablespoon plain flour; 1 teaspoon dried thyme; 400g (14 oz) tin chopped tomatoes; 2 tablespoons mustard; 1 tablespoon tomato puree; 2 tablespoons soy sauce; 1 teaspoon marmite; 850ml (3 1/2 cups) vegetable stock (3 stock cubes); 1 pinch salt and pepper