Assuming that by "yield" you mean the quantity of seaweed sandwich that can be produced, here are some ways to increase the yield:
Use thinner layers of seaweed: Using thinner layers of seaweed will allow you to make more sandwiches from the same amount of seaweed.
Use a smaller portion size: Using smaller portions of filling in each sandwich will allow you to make more sandwiches with the same amount of seaweed.
Optimize the cutting process: If you're cutting the seaweed sheets into smaller pieces to make the sandwiches, be sure to cut them efficiently to minimize waste and maximize the number of pieces you can get from each sheet.
Use a higher-quality seaweed: Some varieties of seaweed have a higher yield than others, so consider using a type of seaweed that is known for producing a high yield of sandwich-sized pieces.
Experiment with different sandwich fillings: Depending on the ingredients you use, you may be able to make more sandwiches with the same amount of seaweed.For example, using more thinly sliced vegetables and less meat or cheese can help stretch the filling further.
Invest in equipment: If you're making a large quantity of seaweed sandwiches, investing in equipment such as a seaweed cutting machine or a sandwich assembly line can help increase your yield and productivity.