In a large pot, add the potatoes. Fill with enough water to cover the potatoes, and season the water with the salt. Over high heat, bring the water to a boil and then reduce to a simmer. Cook for approximately 15 minutes, until the potatoes are fork tender. Drain the water from the potatoes and using a potato ricer, process the potatoes until all lumps are gone. Return the shredded potatoes to the warm pot and stir in butter and a grind of black pepper. Cover the pot and keep warm.

Preheat the oven to 400°F (200°C).

Slice the bell peppers lengthwise on one side of the stem to the base. Remove these caps and dice them for use in the stuffing mix. Using a paring knife, form a deep cavity in the pepper by removing the inside ribs and seeds. Shake out any remaining seeds.

In a large skillet over medium-high heat, add the oil. Once the oil is hot, add the onion, diced bell pepper, and garlic. Sauté just until the onions turn translucent, about 5 minutes. Add the drained tomatoes and continue cooking until the flavors come together, another 5 minutes. Remove the skillet from the heat and let cool (optionally, place the mixture in the refrigerator to expedite cooling).

In a large mixing bowl, add the ground meats and the cooled vegetable mixture. Break the egg into the mixture and add the bread crumbs. Using your hands, combine the ingredients so that they mix evenly.

In each bell pepper, add enough of the mashed potatoes to cover the bottom. Spoon in some of the meat mixture to fill the pepper cavity nearly to the top, and place pepper Jack cheese on top. Next, mound enough of the remaining meat mixture to encase the cheese and create a dome. Lay strips of bacon on top.

Place the peppers onto a foil-lined baking tray with just a bit of water to create steam. Cover the entire tray with a sheet of foil to encase the peppers. Place in the hot oven for 1 hour.

Meanwhile, add the pepper jelly to a microwaveable dish with just a teaspoon of water; microwave on high for about 15 seconds or until the jelly melts. The glaze should now be brushable. 

Remove the stuffed peppers from the oven, and uncover. Brush the bacon and the top of the meat with the pepper jelly glaze. Return to the oven for another 30 minutes, or until the bacon crisps, the glaze sets, and blackened bits begin to appear. Be careful not to burn.

Remove the peppers and serve on individual plates.