- First clean, wash and chop all the vegetables as mentioned in the list above. Keep it aside. 
- To begin, heat oil in a heavy bottom pan over medium heat, add chopped onion and garlic. Saute for a couple of minutes until onions are softened. No need to brown the onions and garlic here. 
- To this add chopped tomatoes and cook till they turn soft and mushy. Once done add roughly torn basil leaves. Transfer this to a bowl and keep it aside. 
- Next, in the same pan add some olive oil. Add chopped carrots, French beans, Zucchini, Broccoli, Mushrooms and Bell peppers one by one. Saute for 3 - 4 minutes until vegetables are lightly softened. 
- After a while, you will notice liquids begin to release from veges and it will look saucy. 
- Season the vegetable mixture with salt and pepper as per your taste. Stir the vegetable mixture, add water if required and allow it to simmer for about 5 to 7 minutes until vegetables are cooked upto 90 %. 
- To this add prepared tomato sauce. Keep stirring until the vegetables are incorporated well with the tomatoes. 
- Meanwhile let's prepare the mashed potato topping for Shepherd's pie.