Po'pei Mussel Platter

INGREDIENTS

• 1/2 cup bacon, diced
• 80 mussels (about 2 1/4 pounds), scrubbed and debearded
• 1 1/2 cups water
• 1 1/2 cups dry white wine or Belgian beer
• 1 bay leaf, preferably fresh
• 4 cups heavy cream
• 1 pound spinach, well washed
• 3 tablespoons unsalted butter
• 3 shallots, finely chopped
• 1 clove garlic, finely chopped
• Pinch freshly grated nutmeg
• 1/2 cup grated Gruyere
• 1/2 cup grated cheddar cheese
• Coarse salt and freshly ground pepper