Ingredients:

  • 2 tbsp olive oil
  • 2 large leeks, sliced (about 400g / 14 oz)
  • 2 cloves garlic, minced
  • 500g potatoes, peeled and cubed (about 1.1 lbs)
  • 2 carrots, diced (about 200g / 7 oz)
  • 2 celery stalks, diced (about 150g / 5 oz)
  • 2 tbsp plain flour (all-purpose flour) (30g / 1 oz)
  • 500ml vegetable stock (about 2 cups + 1/8 cup)
  • 1 tbsp tomato puree (tomato paste) (15 ml)
  • 1 tsp dried thyme
  • Salt and freshly ground black pepper to taste
  • 140g frozen peas (5oz)
  • 1.5kg potatoes, peeled and quartered (about 3.3 lbs)
  • 100ml milk (about 1/2 cup)
  • 50g butter (about 1/4 cup or 4 tablespoons, unsalted)
  • 100g mature cheddar cheese, grated (about 3.5 oz)
  • A knob of butter

Instructions:

  1. Sauté leeks and garlic in olive oil until softened.
  2. Stir in potatoes, carrots, and celery. Cook for a few minutes.
  3. Stir in flour, then gradually add vegetable stock and tomato puree. Add thyme.
  4. Bring to a simmer, then reduce heat and cook until vegetables are tender and sauce has thickened (approximately 20-25 minutes). Season with salt and pepper. Stir in frozen peas.
  5. Boil potatoes until tender. Drain well and return to the pot.
  6. Mash with milk and butter until smooth and creamy. Stir in grated cheese and season with salt and pepper.
  7. Pour the vegetable filling into the oven-safe dish.
  8. Spoon the mashed potato evenly over the filling. dot with knob of butter
  9. Bake in a preheated oven at 200°C / Gas Mark 6 / 400°F until golden brown and bubbly (approximately 20-25 minutes).