Add ½ cup of your tomato sauce with ¼ cup of water to the bottom of a baking dish to accommodate your 4 peppers. You want a diluted sauce layer at the bottom of your dish. Then slice the tops off your peppers and carefully scoop out the seeds and membranes. Sprinkle the peppers with salt inside and out and place them hollow side up in your dish. Set aside.
Preheat your oven to 425 degrees F convection bake.
Heat a large skillet and melt the butter, if using. Add the onions and sauté over medium high heat for 2-3 minutes until softened. Then add the Arborio rice and the garlic powder, mix well and toast for about 30-60 seconds, stirring often.
Add the wine, if using and stirring often, cook until the wine has completely absorbed, approx. 2 minutes.
Now add your broth, approx. ½ cup at a time, stirring often until mostly absorbed. Continue adding another ½ cup of broth each time the previous batch is absorbed. Repeat until all the broth is consumed, adding your mixed veggies with the last portion of broth. This process will take about 20-25 minutes. Taste and adjust for salt and pepper, if needed.
Divide the vegetable risotto between your 4 peppers, pushing down the mixture into each one. Cover with parchment paper, and then foil and bake for 30-45 minutes, removing the paper for the last 5 minutes or so, if you'd like to brown your peppers. (Use 30 minutes total bake time for crisp peppers and 45 minutes for soft peppers.)
Use the extra sauce at the bottom of your baking dish for serving. You may also garnish with fresh basil or parsley, parmesan cheese, and red pepper flakes.
Use care when hollowing out your bell peppers. You don't want them to break, or the stuffing won't hold.Make sure to salt your peppers inside and out, before stuffing them, otherwise you'll have a flavourful filling but bland shell.Use a salty, flavourful broth to make your risotto for best results.Don't dump all the broth into your pan at once. The slower method of cooking risotto is a tried and true technique which will yield the best results for your Italian stuffed peppers.For no oil, sauté the onions in a tablespoon or two of broth.For wine free, use an additional half cup of broth in replacement. But follow the same cooking directions.Leftovers keep refrigerated in a sealed container for 2-3 days, or freeze for up to 3 months.You may also prep these 1-2 days in advance and refrigerate. Then bake the day you plan to enjoy them. Or freeze the fully prepared stuffed peppers for up to 3 months and bake from frozen, adding an additional 10-15 minutes of bake time.