If using 16 oz. shrimp, follow same instructions as 8 oz. shrimp, working in batches if necessary.
If using whole chicken breasts, pat dry and, on a separate cutting board, cut into 1” pieces. For this and diced chicken, follow same instructions as shrimp in Steps 3 and 4, cooking, stirring occasionally, until chicken reaches minimum internal temperature, 5-7 minutes.
If using tofu, line a plate with a paper towel. Cut tofu into 1" dice and place on towel-lined plate. Top with paper towels, then press gently but firmly to remove excess moisture. Follow same instructions as shrimp in Steps 3 and 4, cooking, stirring occasionally, until tofu is golden brown, 6-8 minutes.