Preheat oven to 350°.

Slice jalapeños in half lengthwise and scoop out seeds & veins with a spoon. Arrange cut-side-down on a foil-lined baking sheet.

Roast jalapeños at 350° for 10 minutes, then remove and set oven to broil.

While jalapeños are roasting, cook the sausage in a large skillet over medium-high until browned, about 5-7 minutes. Add bell peppers, onions, and garlic and cook until peppers & onions are soft. Remove from heat and let cool 10 minutes.

Combine sausage mixture, cream cheese, parmesan, and salt in a large bowl. Stuff filling evenly into roasted jalapeño halves, then sprinkle mozzarella on top.

Broil for 2-3 minutes, until mozzarella has melted. Let cool for a minute and serve hot.