For the brown bread dumpling casserole with nuts, heat the oven to 180 °C.
Toast bread slices and cut into small cubes.
Finely chop leek and sauté in canola oil, let cool.
Mix bread cubes, leek and walnut pieces in a bowl.
Whisk egg with skim milk, season with salt, pepper and nutmeg.
Pour the milk-egg mixture over the bread-leek-nut mixture, mix and let sit for about 10 minutes, stirring gently with a spoon occasionally in between.
The bread cubes should not dissolve.
Pour bread mixture into two small coated (or baking paper-lined) ramekins and bake brown bread dumpling casserole with nuts in preheated oven for about 25 minutes until golden brown.