Step 1

Place the peppers directly on a gas flame. Char on all sides until the skin burns. Refrigerate to cool quickly, 10 to 15 minutes. Place on a flat surface and open, seed, peel and discard the skin. (I use a kitchen towel to wipe the skin away. Don’t rinse the peppers under water, as it washes away flavor.) Slice the peppers into 1/2-inch slices. Sprinkle with salt and pepper and the sugar. Set aside.

Step 2

Split the sausages lengthwise. In a large, heavy-bottomed skillet, heat the oil over medium heat. Arrange the sausages cut-side down in a single layer in the oil. Sprinkle with salt. Cook, flipping once sausages with tongs, so each one browns hard on both sides, 10 to 12 minutes. Remove them from the skillet and set aside.

Step 3

In the same skillet, add the onions and fresh garlic with a generous pinch of salt. Cook, stirring from time to time with a wooden spoon, until the onions soften, 8 to 10 minutes. Stir in the peppers and cook for 4 to 5 minutes more. Add the vinegar, granulated garlic, oregano and some Parmesan and stir to combine. Taste for seasoning.

Step 4

While the onions are cooking, spread butter on the cut sides of the rolls, then sprinkle with some crushed red pepper flakes. Toast on a griddle over medium-low heat until lightly golden, 3 to 4 minutes. Stuff the rolls with some of the pepper-onion mixture, then top with the sausages, some more pepper-onion mixture and a sprinkle of Parmesan. Serve.