Place chicken breasts into inner pot of Instant Pot. Cover with water and 1 tsp or more salt, to taste.
Cook on High Pressure for 20 minutes then quick release the pressure. Remove chicken to a heat-proof plate to cool.
Reserve 1 cup of chicken broth from the Instant Pot. Turn Instant Pot to saute setting and allow the remaining broth to come to a boil while you make the dumplings.
In bowl of food processor, add flour, 1 tsp salt and 1/3 cup Crisco shortening. Pulse food processor a few times to mix then start slowly pouring in broth from the Instant Pot until the dough begins to form a ball. As soon as it forms a ball, turn off the food processor!
Roll out dough very thin. Cut into strips of equal size. (I use a pizza cutter.) Drop into boiling broth then add shredded chicken. Cook on saute setting for 12-15 minutes.