How to Make It
Using a sharp knife, peel the oranges and grapefruit, removing all of the bitter white pith. Cut in between the membranes and release the sections into a bowl. Coarsely chop the sections and return to the bowl.
In a large pot, combine the Riesling, water, thyme and garlic and bring to a boil. Add the mussels, cover and cook until the shells open, about 5 minutes. Transfer the mussels to a bowl and remove them from the shells.
Strain the broth and return it to the pot. Add the saffron and orange zest and boil until the broth is reduced to 2 cups, about 8 minutes. Add the cream and simmer until thickened, about 5 minutes. Add the butter and swirl until melted. Add the mussels.
Spoon the mussels and broth into bowls. Garnish with the chopped citrus, brioche croutons, olives and pea shoots and serve.
To make the croutons, cut 1-inch slices of brioche into cubes and transfer to a baking sheet. Bake in a 350° oven for 10 minutes, or until toasted.