The screening of sustainable agro-industrial biorefinery pathways for the production of bio-based products and energy is a complex challenge and needs investigation. Critical tools for predicting the commercialization feasibility of biorefining pathway includes laboratory and pilot-scale experimental results, processes modeling, technoeconomic and market analysis. The objective of the present study was the potential pathways experimental proof of concept of the sunflower meal (SFM), by-product in the sunflower oil production process, at TRL3-4 level, in an effort to assist the bio-based industries in evaluating the profitability of different possible production routes and product portfolios. Taking a reflexive approach, various processes and products were investigated, adding insights in the technical feasibility of conversion towards multi-product pathways at lab scale. Many sets of experiments were conducted in two laboratories, investigating SFM biorefining using physical, biological and thermochemical processes (fractionation, fermentation, enzymatic hydrolysis and pyrolysis) for the production of various added-value products, biochar and energy carriers. Product yields, mass balances, Effective Mass Yield (EMY) and Feature Complexity (FC) were estimated for each pathway. The study demonstrated that SFM cascade refining concept is feasible leading to the production of antioxidants, protein isolate, biochar, bioenergy carriers (pyro-oil and pyro-gas) and also poly(3-hydroxybutyrate) and microbial oil with a Feature Complexity (FC): 6-7. The studied pathways were based on the principle of optimised resource utilisation. Pyrolytic chars showed suitable for soil amendment, thus, closing the loop in agriculture (from land-to-land). The study demonstrated at TRL3-4, alternative pathways for sifting from a mono-to-multiple process and product agricultural industry (Grey biotechnology), in the context of Circular Bioeconomy and provided experimental protocols. •Reflexive TRL2-4 approaches in the content of Circular Bio Economy.•Valorization of sunflower meal through a cascade bio-refinery approach.•Shifting from a mono-to a multiple-product agricultural Industry.•Antioxidants, protein, microbial oil, PHB and bio-char from sunflower meal.