Cook green peas in salted boiling water, drain, and set aside.
Heat butter or oil in a large non-stick pan or wok (or tawa if you have one) and add cumin seeds. You can also use half butter and half oil.
After the cumin seeds start sizzling, add grated ginger.
Saute for a few seconds, and then add chopped celery, green beans, and carrots. Cook them for about 2-3 minutes on medium-high heat.
Then add chopped cabbage and green pepper, and cook for 2-3 minutes, stirring often.
Add chopped tomatoes and salt, and mix well. Cook tomatoes until they are soft and mushy.
Add turmeric powder, red chili powder, coriander powder, and pav bhaji masala and mix well. If the vegetable mixture looks dry, add a tablespoon of water.
Then with a potato masher, mash the tomato mixture lightly. The mixture will become mushy and pulpy.
Add boiled green peas, chopped coriander leaves, and Kasoori methi, and mix well.
Turn the heat on low, add cooked rice, and mix very gently so the rice grains do not break.
Once everything is well combined, taste and adjust the salt as needed. Turn off the heat.
Garnish the tawa pulao with more coriander leaves, squeeze the lemon juice, and serve.