In the bowl of a food processor, add the potatoes, flour, eggs, and shallots. Pulse until everything is just blended and the consistency of the batter is chunky. Season, to taste, with salt and pepper.
In a large skillet over medium-high heat, add a thin layer of oil. Pour about 1 tablespoon of the batter into the skillet for each pancake. Cook until lightly browned on both sides. Remove the pancakes from the pan to a plate and allow them to cool to room temperature.
Cut the salmon into small dice and put them into a bowl. Add the capers, 1 tablespoon of olive oil, a few drops of lemon juice, and season with salt and pepper, to taste. Mix well, taste, and adjust the seasoning. Cover and refrigerate until ready to serve.
Put the baby spinach and the frisee into a small bowl. Add the chives and 1 tablespoon of the dill and season with salt and pepper, to taste. Add a teaspoon of lemon juice and a drizzle of olive oil and toss to coat well.
To serve, put ring mold on a serving plate and add a pancake. Top it with some of the salad and fill it with 2 tablespoons of the tartare, pressing it in gently. Lift off the ring mold. Put a teaspoon of Dill Creme Fraiche onto the plate and run the back of the spoon through it to spread it in a line across the plate. Top the Dill Creme Fraiche with 1/2 teaspoon of the salmon roe. Garnish with the remaining chopped fresh dill. Repeat with the remaining ingredients.