1. Put the oil, ham, onion, tomato, ½ cup of the water, and the rice in a covered casserole.
2. Cook, covered, in the microwave oven, stirring occasionally until the rice is almost tender ("al dente"). This will take about 15 minutes.
3. Add more liquid if the mixture gets too dry. Add the shrimp and cook, covered, in the microwave oven until it turns a bright pink (about 4 minutes), stirring once.
4. Add the salt, pepper, clams and their juice, the remaining water, and the egg. Heat to a simmer and serve at once.
