On leaving the EU, all existing legislation was adopted directly into UK law as “Retained EU Regulations and Directives” which can be found here: https://www.legislation.gov.uk/eu-legislation-and-uk-law
The intent of the UK was always to develop its own regulations and towards this goal, a Bill to revoke and reform the legislation is currently under consideration. UK Government departments including the Food Standards Agency (FSA) responsible for ensuring the preparation of UK legislation that will replace the EU retained law.
The FSA has recently published a paper on the progress of the Bill and the FSA’s programme of work until 2026 to support delivery and associated reforms. https://www.food.gov.uk/board-papers/retained-eu-law-revocation-and-reform-bill-2022
Since leaving the EU, the UK has developed its own regulatory products approval process which currently mirrors the EU legislation. Potentially, the Bill offers the opportunity to introduce changes to the regulatory approval processes to aid transparent, science-based assessments in a timely manner. Notably, in 2022, the first novel food ingredients and feed additives were authorised in the UK. The process was initially slowed by the number of CBD applications the UK had to review following an initiative launched since leaving the EU to regulate this market. However, 2023 should see a more timely evaluation and authorisation of novel foods and feed additives.
More information on the regulated products authorisation process may be found here: https://www.food.gov.uk/apply-for-a-regulated-product-authorisation