Add olive oil to a pan over medium heat. Add beef and break it apart as it cooks, about 5 minutes until browned.
tomato paste, chili powder, and salt to the pan, and stir together with
the beef until well-mixed and tomato paste has dissolved, about a
minute. Continue cooking until nearly all liquid has evaporated, a few
minutes, stirring occasionally. Turn off the heat.
In a large heatproof bowl, microwave cream cheese until soft, about 30 seconds.
Transfer the beef mixture to the bowl. Stir the beef and cream cheese until well-mixed. Set aside.
Preheat the oven to 400 F. Prepare a foil lined baking sheet.
each poblano pepper in half lengthwise. Remove and discard seeds. Stuff
each pepper half with the beef-cheese mixture, and place on the lined
baking sheet. Distribute cheddar cheese on top.
Bake at 400 F until the peppers are tender, 25 to 30 minutes.