How to Make It
Pour chicken stock into a programmable electric pressure cooker (such as an Instant Pot). Whisk in taco seasoning, and place chicken breasts in pot. Cover Instant Pot, and fasten lid. Lock and seal steam valve. Set to HIGH pressure for 12 minutes. (The pot will take about 15 minutes to come up to pressure before the cooking program begins.)
When cooking program ends, carefully release pressure quickly by turning Pressure Release to VENT. (Steam is fully released when pressure valve drops.) Uncover and turn off Instant Pot. When cool enough to handle, remove chicken from bones and shred meat. Toss with accumulated juices in pot. (2 cups shredded meat)
To assemble tacos, place 1/4 cup shredded chicken on each tortilla, top with 1/4 cup shredded lettuce, 1 tablespoon each pico de gallo, sour cream, and cilantro, and 2 tablespoons queso fresco.