Lentil and Sweet Potato Cottage Pie - Meat Free Monday

Ingredients

• 1 large red onion
• 2 carrots
• 2 celery stalks
• 1 red pepper
• 4 cloves garlic
• 200 g/7 oz/scant 1¼ cups dried green or brown lentils
• 2 tablespoons olive oil
• 3 tablespoons sundried tomato paste
• 1 x 400 g/14 oz can chopped tomatoes
• 1 litre/35 fl oz/4¼ cups vegetable stock
• 1 teaspoon dried oregano
• 1 teaspoon smoked paprika
• 2 tablespoons vegan Worcester sauce
• 2 tablespoons smooth tahini
• 2 tablespoons dark soy sauce
• 1 tablespoon balsamic vinegar
• 200 g/7 oz/1⅔ cups frozen peas
• sea salt and black pepper