over med heat add onion and celery. saute till onion is clear but not brown.
add water ant turn heat on high. cover with lid and bring to a boil. add pasta and stir till occasionally until it returns to a boil. reduce heat to med low and cover. set timer for 10 minutes. stir occasionally.
add tuna, no need to drain if it is packed in water.
add drained peas.
stir soup mix until no lumps of soup mix are seen.
stir in cheese. cover and remove from heat. let sit about 1 minute then serve hot.