Step 1

Toast fennel seeds in a dry small heavy skillet over medium heat, shaking skillet often, until fragrant, about 1 minute. Let cool. Finely grind fennel seeds in a spice mill or with mortar and pestle; transfer to a small bowl and stir in salt. Season pork on both sides with fennel salt.

Step 2

Heat 2 Tbsp. oil in a large Dutch oven or other heavy pot over medium-high. Working in batches if needed, cook pork, turning occasionally, until browned on all sides, 15–20 minutes.

Step 3

Transfer pork to a large plate or platter. Carefully pour off all but 1 Tbsp. drippings in pot. Pour in 2 Tbsp. oil, then add onions, carrots, garlic, and oregano. Season with salt and toss to combine. Cook, stirring occasionally, until vegetables start to soften, 6–8 minutes. Stir in Vero Gusto sauce and red pepper flakes. Rinse out a sauce jar with about 1 cup water and add to pot; season with salt. Bring to a simmer.

Step 4

Return pork to pot along with any accumulated juices. Reduce heat to low and bring to a very bare simmer (pork should be mostly submerged; stir to redistribute vegetables and add more water if needed). Cover pot and cook, stirring occasionally and skimming fat from surface, until meat is fork-tender, 2–2½ hours.

Step 5

About 45 minutes before pork is done, bring 8 cups water to a boil in a large pot; season with 2 tsp. salt. Whisking constantly, gradually add polenta. Bring to a simmer and cook, whisking often, until tender, 30–35 minutes.

Step 6

Meanwhile, toss chiles and lemon juice in a small bowl; season with salt. Let sit until ready to use (at least 10 minutes).

Step 7

Remove polenta from heat and stir in basil, parsley, and butter. Gradually add Pecorino, stirring constantly until combined.

Step 8

Scrape polenta onto a large platter. Pluck oregano sprigs out of pork mixture; discard. Arrange pork mixture over polenta and top with pickled chiles.

Step 9

Do Ahead: Pork can be braised 4 days ahead. Transfer to an airtight container and let cool. Cover and chill. To serve, skim off any solidified fat from surface, then return to a simmer over medium heat.\