The nutrient-dense instant porridge was developed by combining flour from Nutrimix Flour, which includes germinated finger millet, green gram, semolina, amaranth seeds, and gingelly seeds. The processing parameters were carefully optimized using Nutrimix flour with Wheat broken, milk powder, and icing sugar to develop the porridge. A Randomized Box-Behenken experimental design was conducted to determine the ideal formulation of Nutrimix Porridge flour. A total of twenty trial sets of experiments were carried out to determine the optimized values of the flour. The optimized ingredients for the porridge were found to be Nutrimix Flour (45%), Wheat Broken (22.5%), Milk Powder (23.5%), and Icing Sugar (9%) respectively. The nutritional analysis of the product reveals a well-balanced composition with a moisture content of 5.8% (± 1.02), energy value of 400.4 kcal (± 1.05), carbohydrates of 72.08% (± 0.45), contributing to the product’s energy content. The protein content was notable at 13.5% (± 1.01), highlighting its potential as a protein source. Additionally, the presence of 6.4% crude fat (± 0.32) adds to the overall macronutrient balance. The total ash content was 2.1% (± 0.88) and crude fiber content was 1.0% (± 0.01). Furthermore, the product contains 507.0 mg of calcium (± 0.34) and 3.1 mg of iron (± 0.19), emphasizing its contribution to essential mineral intake. The product also exhibits significant physical and functional characteristics, as indicated by the provided parameters. Its swelling capacity was recorded at 18.2 ml (± 0.24), water absorption capacity was substantial at 49.3% (± 0.67), emulsion activity and capacity were recorded at 43.2% (± 0.03), while the emulsion stability was 47.6% (± 0.55), and the bulk density of 843 kg/m3 (± 0.22) provides insight into its physical density. Overall, these parameters collectively highlight the diverse and beneficial characteristics of the product, making it a complete balanced meal for lactating mothers and versatile for various applications in food and industrial settings.