Make the pudding: Place wheat berries in a 3-quart saucepan; add boiling water to cover by 2 inches. Bring to a rolling boil. Let boil for 15 seconds, then drain and discard the water. Repeat five times: add boiling water, bring to a boil, boil for 15 seconds, drain.
Cover wheat berries again by 2 inches with boiling water. Stir in salt and bring to a boil. Boil for 15 seconds, then remove from the heat without draining. Place the pan on a folded blanket, cover, and wrap with towels or blankets. Let sit at room temperature for 8 hours or overnight.
The next day, drain any water that hasn't been absorbed. Grind wheat berries thoroughly in a food processor. (If you use a blender, work in very small batches.) Transfer ground wheat to a bowl and clean the food processor.
Grind walnuts in the food processor until fine. Add confectioners' sugar and process until mixture resembles fine meal. Add ground wheat and pulse until well combined.
Spoon pudding into a glass trifle bowl or serving dish. Stick slivered almonds into pudding to resemble a porcupine.
Make the topping: Beat cream in a chilled glass or metal bowl with an electric mixer until stiff peaks form.
Serve pudding in 2-tablespoon portions in small decorative bowls or custard cups. Top each serving with whipped cream.