Preheat oven to 375 degrees Fahrenheit.
Place the halved jalapeno peppers on a baking sheet, with the cut side up. Set aside.
In a skillet, heat the olive oil over medium-high heat. Add the chopped onion and pepper. Cook until the onions and pepper begin to soften. Add the ground turkey and stir and break up the turkey. Cook until the turkey is cooked through and firm, about 8 minutes—Season to taste with salt and pepper.
Add about one tablespoon of the turkey mixture to the halved jalapeno peppers. Depending on the size, you might have extra turkey mixture left over. Once the peppers are filled, place the baking sheet in the oven for about 30 minutes. The jalapeno peppers will soften, and the top will get browned.
Remove from the oven, top with the shredded cheese, and return to the oven for about 5 minutes or until the cheese melts.
Top with the chopped cilantro and serve immediately.