In a large broiler-proof skillet, cook broccoli and shallots in hot oil over medium heat for 8 to 10 minutes or just until tender, stirring occasionally. Pour egg mixture over the broccoli mixture in skillet. Cook over medium-low heat. As mixture sets, run a spatula around the edge of the skillet, lifting egg mixture so uncooked portion flows underneath. Continue cooking and lifting edges until egg mixture is almost set (surface will be moist). Arrange tomatoes on top of egg mixture.