What's the fastest method possible to getting bigger body mass?

Healthy eating + pt: Foods to help w healthy weight gain: almonds, cashews, pecans, sunflower seeds, flax seeds, walnuts, hummus, avocadoes, granola, trail mix, dried fruits, extra virgin olive oil, canola oil, protein shakes, protein bars, lean meats, poultry, fish, smoothies (with added silken tofu or powdered milk), greek yogurt (full –fat), pasta/ bagels ; juice rather than soda. Some people add whey proteins.