Toss nuts in 1/2 cup of flour then set aside. Cream together butter and sugar. Add milk and egg white. Sift together flour, salt and baking powder then mix into the egg mixture and stir will. Fold in the nuts. Steam for 1 1/2 hours in a pudding basin or pudding cloth.
Combine all ingredients and bring to a boil. Reduce heat and allow to simmer until slightly thickened. Drizzle over the cooked pudding to serve.
To prepare a pudding cloth, dip it in boiling water, then ring out (wearing gloves). Lay it flat on your bench and rub flour into the centre in a circle about 40cm wide, this creates the pudding skin. Place pudding ingredients in, wrap up then tie with string. Immediately submerge in boiling water.