How to Make It
Preheat the oven to 400°.
Whisk the quinoa into a large pot of boiling salted water and cook for 8 minutes. Add the broccoli and continue boiling until the broccoli and quinoa are tender, about 7 minutes. Drain the quinoa and broccoli in a fine sieve and let cool completely.
In a bowl, whisk the egg with the oil, cheese and 1/2 teaspoon each of salt and pepper. Fold in the quinoa and broccoli and transfer the mixture to an 8-inch-square baking dish; cover tightly with foil. Bake until the gratin is hot, about 20 minutes; Serve.