1. Bring a lightly salted water to a boil in a large saucepan.
2. Add the broccoli, cover, and let it cook over low heat. Beat the 2 eggs in a large bowl, add the cream, salt, pepper, and one-third of the grated cheese. Mix well.
3. When the broccoli is tender, drain it as much as possible. Preheat the oven to 180°C (350°F). Heat a little oil in the saucepan and add the roughly chopped onion. Sauté over very low heat, being careful not to brown it!
4. Add the two pressed garlic cloves and the broccoli to the saucepan. Season lightly and mix well.
5. Pour the contents of the saucepan into a gratin dish and spread it evenly. Pour the egg mixture over it and spread it evenly.
6. Sprinkle with breadcrumbs and the remaining grated cheese. Place the dish in the oven, still at 180°C (350°F), and let it cook for 30 to 45 minutes.
7. Check the cooking from time to time... The dish should be quite dense (at the end of cooking), similar to a large omelette.