Seera, is a traditional Indian fermented food, has high carbohydrate and reducing sugar content, however, lacks functional components like antioxidant properties. The present study aims to optimize and evaluate the multigrain seera with added values. The optimization of seera was made using mixture design, with green gram (X1, 15–30%), sorghum (X2, 15–25%) and finger millet (X3, 5–10%) as independent variables. The responses checked were total phenolic content (Y1), protein content (Y2) and overall acceptability (Y3). The optimum run with green gram (25.58%), sorghum (15%) and finger millet (9.41%) resulted in TPC (1.2 ± 0.12 mg GAE/g), protein content (11.40 ± 0.10 g) with overall acceptability (8.32 ± 0.30). The optimized multigrain seera depicted higher fibre (4.23 ± 0.08%), ash (1.90 ± 1.1%) and protein (11.40 ± 0.10%) than the control seera. The rheological properties of seera depicted shear thinning and elastic behaviour. Texture profile analysis showed that cohesiveness (0.415 ± 0.01) increased significantly (along with decreased springiness (0.251). Morphology of seera showed broken and deformed starch granules with few cracks due to fermentation phenomena that leads to superficial corrosion.