Stir the salsa, broth, chiles, onion, chili powder, cumin, cinnamon, and salt (if using) in an Instant Pot. Set the two blocks of frozen turkey in the pot so that they look like an A-frame or a lean-to, sticking up out of the liquid and balancing against each other along their upper edges. Lock the lid onto the pot.
Option 1Max Pressure Cooker Press Pressure cook on Max pressure for 20 minutes with the Keep Warm setting off.
Option 2All Pressure Cookers Press Poultry, Pressure cook or Manual on High pressure for 25 minutes with the Keep Warm setting off.
Use the quick-release method to bring the pot’s pressure back to normal. Unlatch the lid and open the cooker. Use the edge of a large, metal spoon and a meat fork to break the ground turkey into tiny bits.
Press the button SAUTÉ, set it for MEDIUM, NORMAL, or CUSTOM 400°F. Set the timer for 5 minutes.
Bring the turkey mixture to a simmer, stirring quite often. Stir in the cornmeal and simmer until thickened, 2–3 minutes. Turn off the SAUTÉ function, set the lid askew over the pot, and set aside for 5 minutes to thicken some more. Serve warm in tortillas with shredded lettuce and cheese.