"हम मछली नमक में पकाएँगे।"
अनुवाद:We will cook the fish under salt.
"We will cook the fish with the salt". Here "with the " is correct. "Under" word is totally wrong.
Your wrong bro if we use 'with' it will be wrong the correct word is as they gave us...we will cook the fish with the salt ka meaning hindi me ye hoga k hum machali namak kai sath pkayenge ...I hope you better understand now