Place the mussels in a skillet large enough to hold them in a single layer, add 1/4 cup water, cover and cook over high heat until the mussels are steamed open. Strain the cooking liquid through several thicknesses of cheesecloth and set aside. Once the mussels are cool enough to handle, remove from the shells and set aside.
In a 12 to 14-inch saute pan, heat 1/4 cup olive oil over medium heat and add the garlic, chile pepper, parsley, and bay leaf and cook over medium heat 5 minutes. Add the steamed mussels and strained cooking liquid and season with salt and pepper, to taste. Bring to a boil and add the white wine. Cook for 2 or 3 minutes, just long enough to meld flavors but not long enough to over-cook mussels.
In a separate saute pan, heat the remaining olive oil over high heat and fry each slice of bread, one at a time, on both sides until golden brown. Drain on paper towels and season with salt and pepper. Sprinkle with a few drops of the vinegar. Remove the mussels from the pan with a slotted spoon and top each slice of bread with mussels. Serve immediately.