Regarding cross-sectoral collaboration, much can be learnt from the BFN experience. Section 4.2.3 Nutrition governance.
At the policy level, all countries established cross-sectoral national policy working groups which revised existing national legislation to identify entry points for the mainstreaming of biodiversity for food and nutrition and Bioversity International contributed to the writing and endorsement of the Voluntary Guidelines for Mainstreaming Biodiversity into Policies, Programmes and National and Regional Plans of Action on Nutrition in 2015 by the Commission on Genetic Resources for Food and Agriculture (CGRFA)
Happy to contribute more at a later stage if needed.
More information can be found here:
http://journal.frontiersin.org/article/10.3389/fnut.2016.00014/full
Teresa Borelli