1Fill a bowl with ice water. Bring a pot of water to a boil, then lightly salt it. Blanch the sugar snap peas in the boiling water for 2 minutes. Use a slotted spoon to transfer the sugar snaps to the ice water bath (keep the water at a boil). Once cool, use a slotted spoon to transfer the sugar snaps to a bowl.
2Add more ice to the water bath. Repeat the blanching process for the shelled peas, blanching them for 3 minutes or until tender, and shocking them in the ice bath. Transfer the cooled peas to a small bowl and coarsely mash them with a fork.
3In a blender or food processor, combine the sugar snap peas, milk, and cream, and purée until smooth. Transfer the mixture to a large mixing bowl and whisk in the egg. Add the flour, baking powder, sugar, and a pinch of salt, and whisk to combine. Fold the mashed peas into the batter.
4Heat the oven to 250°F.
5In a large ovenproof skillet over medium-high heat, melt 1/2 tablespoon of the butter. Drop tablespoons of batter into the pan. When the edges are lightly browned after 2 minutes, flip the pancakes, lower the heat as far as it will go, and cook until the pancakes are done in the center and the bottoms are browned, about another 2 minutes. Transfer the pancakes to a baking tray lined with paper towels, and sprinkle with salt and pepper to taste. Keep the pancakes in the warm oven until all the batter has been used.
6Serve topped with a dollop of crème fraîche, a slice of salmon, and a sprinkling of chives.