Increasing sustainability demands of stakeholders and government regulators are driving Food Manufacturing Companies (FMCs) towards embedding sustainability practices across the entire food value chain. This is most relevant in emerging economies such as India, as the sustainable growth of the food supply chain (SC) is predominantly dependent upon its multiple tiers of suppliers. Regrettably, the most impactful tier of suppliers, which are the grass-root suppliers, lie outside the reach of the sustainable efforts of the FMC. Significantly, the incorporation of the sustainability initiatives needs consistent and coordinated efforts of all the tiers of suppliers and stakeholders, especially in the current situation where a global pandemic badly hits farmers. This can be achieved by adopting Collaborative Sustainable Practices (CSPs) for channelization of joint efforts of FMC and stakeholders towards sustainability of grass-root suppliers using supply chain practice view. However, minimal documentation exists regarding the same, and the present study intends to fill this gap. Based on a case study of an Indian flour milling company, the focus of the research work is (1) identifying CSPs that FMC can adopt, (2) ascertaining the role of interim suppliers for ensuring sustainability up to the last tier of suppliers, and (3) developing a structural model utilizing combined efficiencies of Total Interpretive Structural Modeling technique and Fuzzy-MICMAC analysis, which the FMC can adopt for effectively implementing both the traditional practices as well as the CSPs. Through the result findings, decision-makers can visualize the impact and strength of each CSP and its interactions with other CSPs. It can enable them to cascade effective managerial responses into the respective tiers of SC for successful implementation of the CSPs and transmission of sustainability benefits to include the grass root suppliers. The study provides significant theoretical implications contributing to the existing literature on sustainability in a multi-tier food SC. Further, inputs to policy formulators for enhancing sustainability of farmers are outlined.