Put oil in a pan and add vermicelli. Roast vermicelli on medium low flame by stirring continuously till it becomes light brown in colour. Keep on stirring to get roasted uniformly.
Once roasted transfer to a plate.
In the same pan put oil and make it slightly hot.
Now add mustard seeds and let it splutters.
Add curry leaves, green chilly and sauté for few seconds.
Add chopped veggies (potato, carrot, French beans, onion) and sauté for a minute.
Cover the lid and let the veggies cooked for 2 minutes on medium low flame.
Uncover the lid and add red bell pepper and green capsicum, green peas. Sauté for a minute. You can add veggies as per your taste.
Now add roasted vermicelli and mix it well.
Add 2-3 cups of water, salt, black pepper, red chilly powder and mix it well.
Cover the lid and cook for 3-4 minutes on medium low flame.
After 4 minutes open the lid and you will see vermicelli has cooked properly and water gets evaporated. If there is any moisture then cook on high flame by stirring continuously but gently till water evaporates.
Lastly add spring onions, coriander leaves, and lemon juice, mix it well.