Pour water in a vessel, and bring it to a boil.
Add salt, sugar, red chili powder, turmeric and garam masala powder, and mix well.
Heat oil in a kadhai, and to it add mustard seeds, jeera, hing, and curry leaves.
Add chopped onions, and sauté till they turn pink and translucent.
Add the tomatoes and cook till soft.
Add the capsicum and sauté for about 30 seconds. (You can use red and yellow capsicum (bell peppers) too.)
Add the seviyan and sauté till they turn golden brown.
Add the boiled water and turn the flame to medium. (Ensure that the water is warm, if not boiling.)
After the water has considerably reduced, turn flame to low, and add assorted vegetables. (As mentioned above, if you want to use veggies like broccoli, corn etc., parboil them first.)
Simmer until seviyan are well cooked and soft.
Garnish with fresh grated coconut and chopped coriander. (I put a little ghee on my upma before serving it to Shantanu (Shweta's son).)