For the fondue: In a saucepan over medium-high heat, bring the heavy cream to a boil. Reduce the heat to low and stir in the cheese, parsley, and pepper until the cheese blends in. Remove from the heat, stir until smooth. Cover and keep warm.
For the relish: Split the avocado in half, remove the pit, and spoon the flesh from the skin. Dice into 1/4-inch cubes, toss with the lemon juice, and set aside.
In small saute pan over high heat, bring the oil to a shimmer, and then add the bacon and shallots, cooking until the shallots are translucent and the bacon is crisp, about 6 minutes.
Using a slotted spoon, transfer the bacon and shallots from the pan into a bowl. Stir in the vinegar, salt, and sugar, mixing well. Drain excess liquid before serving
For the creme fraiche: In a bowl, add the creme fraiche, heavy cream, white pepper, hot sauce, and lime juice. Whisk well to blend. Set aside.
For serving: Place the Sour Cream Potato Cakes (or crostini) on a platter, top with a smear of fondue, a bit of the bacon relish, and a drizzle of creme fraiche.
In the bowl of a food processor, add the potatoes, eggs, sour cream, flour, and salt.
Pulse until the mixture is just blended and you don't have chunks. It should look like cooked oatmeal. Do not over-mix or the potatoes will get gummy!
Heat a good swirl of oil in a nonstick pan or griddle over medium heat.
Drop a heaping tablespoon of batter into the pan to make bite-sized cakes. Cook the cakes until golden brown and cooked through, about 2 minutes on each side.
Drain on paper towels. Season with salt.