Heat a large pan to medium heat and add olive oil. Add onion and jalapeno pepper and cook about 5 minutes to soften.
Add garlic and stir. Cook another minute. Set the cooked vegetables aside.
Season chicken with salt and pepper and set into the hot pan. Sear each side a couple minutes, then add chicken stock.
Reduce heat and simmer the chicken about 20 minutes, or until the chicken is cooked through. Shred with a fork and turn up the heat to reduce the amount of liquid in the pan. If needed, you can add a bit more stock. You can there to be a good amount of moisture.
Add cooked vegetables, taco seasonings and a few dashes of hot sauce. Simmer about 10 minutes or so to allow the flavors to develop.
Remove from heat and add half the cheese. Stir to incorporate.
Slice the bell peppers in half lengthwise and core them out. Stuff each with the chicken taco mixture.
Heat a grill to medium and grill the peppers with the lid closed about 15 minutes, or until the peppers are softened and beginning to char.
Serve topped with cilantro, extra cheese, crema or sour cream, and hot sauce!