Follow these steps carefully for perfectly cooked, flavour-packed peppers:

1. Preheat Oven & Prep Peppers: Preheat your oven to 375°F (190°C). Wash the bell peppers thoroughly. Slice them in half lengthwise, from stem to base. Remove the stems (or leave a small part for presentation, if desired), seeds, and white membranes. Arrange the pepper halves, cut-side up, in a 9×13 inch baking dish or on a baking sheet lined with parchment paper. You might want to lightly grease the dish.
2. Optional Pre-Bake (for Softer Peppers): If you prefer very tender peppers, you can pre-bake them. Add about 1/4 inch of water to the bottom of the baking dish (if using). Cover loosely with foil and bake for 15-20 minutes while you prepare the filling. This step helps ensure the peppers are fully cooked through without the filling becoming dry. If you like your peppers with a bit more bite (tender-crisp), you can skip this step.
3. Brown the Beef: While the peppers might be pre-baking (or if you skipped that step), heat the olive oil in a large skillet or Dutch oven over medium-high heat. Add the lean ground beef and cook, breaking it apart with a spoon, until it’s nicely browned, about 5-7 minutes. Drain off any excess grease.
4. Sauté Aromatics: Push the browned beef to one side of the skillet. Add the chopped yellow onion and chopped green bell pepper (if using) to the empty side. Sauté for 4-5 minutes until the onions become translucent and the peppers soften slightly.
5. Add Garlic: Stir in the minced garlic and cook for another minute until fragrant. Be careful not to burn the garlic. Mix the vegetables and garlic thoroughly with the browned beef.
6. Create the Sloppy Joe Sauce: Reduce the heat to medium-low. Stir in the ketchup, water or beef broth, brown sugar, Worcestershire sauce, yellow mustard, chili powder, salt, and black pepper. Mix everything together until well combined.
7. Simmer the Filling: Bring the mixture to a gentle simmer. Let it cook, stirring occasionally, for about 10-15 minutes. This allows the flavours to meld and the sauce to thicken slightly. Taste and adjust seasonings if needed – more brown sugar for sweetness, more chili powder for heat, or a dash more Worcestershire for depth.
8. Incorporate Some Cheese (Optional): Turn off the heat. Stir in about half (1/2 cup) of the shredded cheddar cheese into the sloppy joe mixture. This adds extra creaminess and helps bind the filling.
9. Stuff the Peppers: Carefully remove the peppers from the oven if you pre-baked them (discard any water in the dish). Using a spoon, generously fill each bell pepper half with the prepared sloppy joe mixture. Mound it slightly, as it might settle a bit during baking. Make sure all pepper halves are filled evenly.
10. Top with Cheese: Sprinkle the remaining half (1/2 cup) of shredded cheddar cheese evenly over the top of the filling in each pepper half.
11. Bake the Stuffed Peppers: Place the baking dish or baking sheet with the stuffed peppers back into the preheated oven (375°F / 190°C). Bake uncovered for 20-30 minutes. The baking time will depend on whether you pre-baked the peppers and how tender you like them. The peppers should be tender when pierced with a fork, the filling should be hot and bubbly, and the cheese on top should be melted, golden, and delicious. If the cheese starts browning too quickly, you can loosely tent the dish with foil for the last 10 minutes.
12. Rest and Garnish: Once baked, carefully remove the peppers from the oven. Let them rest for 5-10 minutes before serving. This allows the filling to set slightly and makes them easier to handle. Garnish with chopped fresh parsley or sliced green onions, if desired, for a pop of colour and freshness.
13. Serve: Serve the Sloppy Joe Stuffed Peppers warm and enjoy!