Chop the garlic, onion, red bell pepper and tomatoes.
Blend the chipotle peppers and adobo sauce. Set aside.
Split the chicken breast pieces into halves. Set aside.
Add all the spices to a plate... onion powder, marjoram, cumin powder, oregano, and salt. Set aside.
Set the Instant Pot to SAUTE mode, once hot, add oil followed by garlic, onion and red bell pepper. Saute for 5 minutes.
Once softened, add tomatoes and cook for another 5-6 minutes.
Now add the chipotle peppers + adobo sauce and spices to the tomato mixture. Stir and cook for a minute.
Immediately add the chicken breasts.
Stir and coat the chicken well with the tomato mixture. Do this for about 30 seconds. Arrange the chicken on top of the tomato mixture.
Cover the Instant Pot with the lid. Set the venting knob to the sealing position. Hit CANCEL. Set to HIGH PRESSURE and cook for 10 minutes. Let the chicken release naturally or wait 20 minutes before opening.
While the chicken is cooking, prep your toppings.
This is what you should have once the chicken is cooked.
Remove the chicken and place into a bowl. Shred the chicken using 2 forks.
Transfer the chicken back to the sauce.
Stir well.
Set the Instant Pot to SAUTE mode for a couple minutes to absorb the water in the gravy. Hit CANCEL once done. Once done this is what you should have. Add cilantro and lime juice.
To assemble, take a couple baked tostadas and heat them in a toaster oven at 400 degrees for a couple minutes. Then top with shredded lettuce.
Followed by the shredded chicken we prepped.
At this time if you want cheese, top the chicken with Mexican cheese and pop it back into the toaster oven for a few minutes. If not, go dairy-free - top with , onions, cilantro, and avocado. Squeeze some more lime if need be.
Notes
* For this recipe I used Guerrero's Baked Tostadas. You can find this brand at most grocery stores, Smart & Final in California, Mexican/Latin grocery stores.