Vegetarian Lentil and Vegetable Lasagna

Name: Vegetarian Lentil and Vegetable Lasagna
Ingredients: Low-calorie cooking spray; 1 Onion ([Diced]); 2 Garlic Cloves ([Minced]); 1 Yellow Pepper ([Deseeded, Sliced]); 1 Carrot ([Finely Sliced]); 1 Small Courgette ([Grated]); 150g Mushrooms ([Sliced]); 100g Frozen or Fresh Broad Beans, Shelled; 150g Dried Red Lentils; 800g Chopped Tomatoes ([2 x 400g Cans]); 1 tbsp Tomato Puree; 1 tsp Dried Oregano; 1 tsp Dried Basil; 300ml Hot Vegetable Stock; 500g Fat Free Natural Yoghurt ([Room Temperature]); 2 Eggs ([Beaten]); 1 tsp Mustard Powder; 10 Fresh Lasagna Sheets; 100g Reduced Fat Cheddar Cheese ([Grated]); Salt and pepper to taste