Finely slice spring onion with some greens diagonally. Reserve the remaining greens. Finely shred cabbage. Thinly slice carrot diagonally and further cut into juliennes. Finely chop celery and ginger.
Heat peanut oil in a non-stick wok. Add sliced spring onions and sauté on high heat for ½ minute. Add chopped ginger and celery, stir and sauté for a minute.
Add shredded cabbage and carrot juliennes, stir and sauté for ½ minute. Add mutton, rice, barley, all spice powder, five spice powder, salt, pepper powder, oyster sauce and soy sauce and toss to mix. Cook for 2-3 minutes.
Add lemon juice and toss to mix. Switch off heat and cool the mixture to room temperature.
Take refined flour in a bowl. Add little water and mix well into a thick paste.
Finely chop reserved spring onion greens.
Place a spring roll sheet on the worktop. Place a spoonful of cooked mutton mixture on one side and top with some chopped spring onion greens. Apply flour paste on the edges, bring both ends together and roll tightly sealing the edges. Prepare the rest of the rolls similarly.
Heat sufficient oil in a wok. Deep-fry rolls till golden and crisp. Drain on absorbent paper.