For the arancini: Line a sheet pan with parchment. Heat the olive oil in a large saucepan over medium-high heat. Add the guanciale and cook, stirring occasionally, until the fat renders out, about 5 minutes. Add the shallots and garlic with a pinch of salt and the red pepper flakes if using and sweat slowly until tender, 8 to 10 minutes.
Add the rice and 1/2 tablespoon of the butter, stir to coat and cook until the rice begins to toast, 2 to 3 minutes.
Stir in the wine and cook until it is absorbed. Add the heated chicken stock 1/2 cup at a time and cook, stirring constantly, until the liquid is absorbed, 3 to 4 minutes. When the rice is about 75-percent cooked and al dente (you may not use all the stock), stir in the tomato paste, sun-dried tomatoes and vinegar. Remove it from the heat and add the remaining 3 tablespoons butter and the Parmesan. Season to taste with salt. The rice should be strongly seasoned and creamy with a touch of texture but not crunchy or watery. Spread the risotto on the prepared sheet pan and allow to cool; cover and refrigerate until needed.
Heat the neutral oil in a large heavy-bottomed pot to 350 degrees F. To make the arancini, use your hands to roll the cooled risotto into packed balls about the size of a golf ball, around the robiola. Refrigerate for 20 minutes or freeze for 10 minutes.
Put the flour, eggs and breadcrumbs in separate shallow bowls. Dip the balls first into the flour, then the eggs and the breadcrumbs.
Fry the arancini in about 3 batches, turning occasionally, until golden brown on all sides, 3 to 4 minutes. Drain on paper towels and season lightly with salt. Be sure to let the oil return to temperature between batches.
For the yogurt: Mix the yogurt with the Aleppo pepper and 1/4 teaspoon salt and reserve.
For the gremolata: Combine the parsley, Parmesan and lemon zest in a medium bowl. Stir in the olive oil and season with salt.
Spoon some yogurt onto a plate. Arrange the arancini on top of the yogurt and top with the gremolata.
I prefer to use medium-grain risotto rice, such as Vialone Nero, but short-grain risotto rice, such as arborio rice, also works well.