Wash strawberries, remove leaves/stem and cut in quarters. Put strawberries into instant pot
Add sugar and lemon juice to instant pot, stir together, and let rest for 10 minutes
Stir again, then close lid and set valve to seal. Cook on manual high for 1 minute
Natural release for 15 minutes and then quick release remaining pressure. Open lid and turn on saute function on high. Stir jam while it sautes
Mix corn starch and water together then add to jam once it start to boil. Stir continuously until jam thickens, about 5-10 minutes
Turn off instant pot and let jam cool for about 30 minutes
Put jam into jars, cool completely, and store in the refrigerator for up to 30 days