Thoroughly pat the beef chunks completely dry with paper towels. Toss the dried beef in a bowl with kosher salt, black pepper, and the all-purpose flour until evenly coated.

Heat the vegetable oil in a heavy-bottomed Dutch oven over medium-high heat. Add the beef chunks in a single layer and sear undisturbed for 3-4 minutes per side until a dark mahogany crust forms. Remove the beef and set aside.

Lower the heat to medium. Add the sofrito to the residual beef fat in the pot. Stir constantly for 2 minutes until fragrant. Sprinkle in the packet of Sazón and stir to combine.

Pour in the tomato sauce and beef broth. Immediately use a wooden spatula to scrape the bottom of the pot, lifting all the caramelized brown fond into the liquid. Return the browned beef chunks to the pot.

Bring the liquid to a rolling boil, then immediately reduce the heat to the lowest possible setting. Cover tightly with a lid and gently simmer for 1.5 hours.

After 90 minutes, check that the beef is starting to become tender. Gently fold in the cubed yellow potatoes, sliced orange carrots, and pimento-stuffed green olives. Cover and simmer for an additional 25 to 30 minutes.

Once the potatoes are fork-tender, check the broth consistency. If a thicker gravy is desired, simmer uncovered for 5 minutes. Turn off the heat and garnish generously with chopped fresh cilantro leaves before serving.