From the screen with the airplane. Heard inside the Charter building. On the left at the back of the screen, interact with the fridge and get the cheese. Now head back outside.
To the far left is a set of steps, take these to get to the next screen.
At the end of a narrow plank, will be a float that is Matoke’s. Use the cheese with the float.
Exit this screen, and back to the airplane. Take the exit to the bottom right to enter the alley. Take the exit to the right and you will enter the screen with the diner. At a table on the far right will be Matoke. Speak with him, and tell him that he’s caught some thing. He will offer you the fishing line and your achievement will unlock.
Har Miggido said you need to talk to Matoke first. Wrote the guide from memory and forgot to add that