Cook the cauliflower rice according to package instructions.
Slice the tops off the bell peppers and carve out the seeds. Remove the stems from the tops and roughly chop the pepper tops. Set aside.
Turn the pressure cooker to "sauté" mode and add the oil. Once hot, add the onion and chopped bell pepper. Sauté until the onion begins to brown.
Add the ground beef, breaking it up as it cooks, about seven to eight minutes. Add the chilli powder, coriander, cooked cauliflower rice, and diced tomatoes. Cook until the mixture starts to simmer. Turn off the pressure cooker. Scoop the beef mixture into the peppers and wipe out the pressure cooker.
Set in the wire trivet and add one cup of water. Set the peppers on top of the trivet. Close the lid and set to "sealing". Press manual/pressure cooker and cook for eight minutes on high pressure.
Once it is done, release the pressure manually. Remove the lid carefully. Top the peppers with cheese. Close the lid and allow the steam to melt the cheese for one to two minutes. Garnish with cilantro and enjoy!
