Peel and chop the onion, and fry in the oil and butter in a saucepan over a medium heat, until soft (about 3-4 minutes). Stir in the curry powder and flour, and cook very gently for a further 2 minutes, stirring all the time. Gradually stir in the soup, bring to the boil, reduce the heat to a simmer, put on the lid, and cook gently for about 20 minutes, stirring occasionally, to make a thick sauce.
Hard boil the eggs for 10 minutes. Rinse them under cold running water, peel them, wash off the shell and cut in half lengthways. Cook the rice for 10-12 minutes in a large pan of boiling salted water. Drain and keep hot, fluffing with a fork to stop it going lumpy. Add the mixed vegetables to the curry sauce, bring back to the boil and simmer for a few minutes to cook the vegetables.
Put the rice onto a warm plate, spreading round with a spoon to form a ring. Arrange the eggs in the centre and cover with the vegetable curry sauce. Serve with any side dishes you like.