Cut the St. Pierre portion into 3 pieces lengthwise.
Cut the foie gras into 2 pieces, matching the shape of the St. Pierre portion.
Season the fish portion with salt and white pepper.
Atop a sheet of plastic wrap, build the fish and foie gras pieces together in alternating layers of attain a stacked pattern.
Use the plastic wrap to contort the block into a rectangle shape.
Wrap tightly with the plastic wrap and cryovac into a sous vide bag.
Cook the rectangle at 48 °C/ 118 ℉ in a water bath for approximately 2 hours.
Once cooked, allow to stand at room temperature until at room temperature, then place the bag in an ice bath.
Once cooled, remove the bricks and remove the plastic wrap.
Cut the cabbage leaf into a shape that will fully wrap around the rectangle.
Wrap the leaf tightly over the rectangle with plastic wrap.
Once wrapped, lightly press the rectangles using weights to even the shape and to set the cabbage.
Allow to press for about 30 minutes.
Once pressed, cut the very ends off the sides of the rectangle to achieve a flat side on either end.
Then cut the rectangle diagonally to achieve 2 triangle shapes.
Remove the plastic wrap from the two triangles gently.
Reserve for service covered.