This chapter highlights the lack of sustainability in the industrialised food systems. It underscores the need for agroecological thinking to drive sustainable food system transitions. Certain interlocks, such as; “expectations of cheap food”, “measures of success”, “path-dependency” and “short-term thinking”, prevent the transition. Public procurement, as a potent demand-side mechanism, has the potential to tackle these interlocks. The analysis shows that the EU procurement regulatory framework allows public buyers to include sustainability considerations in technical specifications and thus leaves the option to alter what is needed to be considered a successful public food bidder. Similarly, the EU concept of “most economically advantageous tender” eclipses evaluation based on acquisition price only and emphasises holistic evaluation based on, for instance, quality, environmental and social characteristics. Furthermore, the EU institutions are challenging “path-dependency” and “short-term thinking” in public procurement of food via its multiple policies (for instance, the Farm to Fork Strategy and EU GPP criteria). Still, utilising public procurement for transforming food systems depends on the discretionary decisions of individual contracting authorities, and long-sighted political leadership at a national level. The case of organic conversion in Danish public kitchens is described as an example of positive achievement.