1. For the risotto, melt butter in a saucepan over medium-high heat. Add onion; cook and stir for 2 minutes until the onion begins to soften, and then stir in the rice.
2. Continue cooking and stirring until the rice is glossy from the butter, and the onion begins to brown on the edges, about 5 minutes more.
3. Pour in the white wine; cook, stirring constantly, until it has evaporated. Stir in 1/3 of the hot stock; reduce heat to medium. Cook and stir until the stock has been absorbed by the rice, 5 to 7 minutes.
4. Add half of the remaining stock, and continue stirring until it has been absorbed.
5. Finally, pour in the remaining stock, and continue stirring until the risotto is creamy.
6. Finish by stirring in the Parmesan cheese, the cooking cream, mascarpone cheese and seasoning to taste with salt and pepper.

Bitter cocoa sauce

1. Melt butter in a saucepan over medium-high heat.
2. Add the diced shallot; cook and stir for 2 minutes until the shallot begins to soften. Add the port wine and some stock.
3. Reduce the heat. Add the soft butter and stir gently.
4. Add the bitter chocolate and stir well. Season well and serve.

Scallops and shrimps

1. Season them with salt and pepper, then cover in sesame seeds.
2. Heat the olive oil in a saucepan over medium-high heat and delicately panfry 2 minutes on both sides until golden-brown.

Assembling the dish

1. Arrange the risotto in the center of a deep round plate.
2. Top with the shrimp and scallop and the sauce around the risotto. Serve warm.