Eliza
I did little experiment last year where I put leaves down as a mulch on 1.5sqm of bed in late October and sowed mustard as ‘cover’ in early March. When the mustard harvest was complete in early-to-mid April, I sowed onion seed direct, in clumps. Growth so far has been excellent, so if you want, you can decrease your need for leaf mould by creating a ‘seed bed’ in situ on your main growing beds.