Hi Ashley Li,
The SA101 is not applicable.
You will only declare the UK part of the Hong Kong income as the duties are carried out here.
You do not include any of the income from when you were still in Hong Kong as this is not taxable in the UK as part of the double taxation agreement.
You will therefore show the income as self employment on the SA103 and if tax has been paid in Hong Kong on the income since you came to the UK, then you wil also complete the SA106.
Tax on foreign income