Preheat the oven to 275 degrees Fahrenheit.
To season the roast, remove it from the refrigerator and pat it dry. Place aside.
Mix together 3 garlic cloves, 1 teaspoon coarse sea salt, 1/4 cup olive oil, and freshly cracked pepper in a small bowl. Stir until combined. Rub generously over the entire roast.
Slice the roast into 1″-deep slits using a sharp knife. Place the remaining garlic chunks within the slits to allow the flavor of the garlic to permeate the meat.
To sear the roast, warm a large Dutch oven over high heat. For best results, roast the meat directly in a hot Dutch oven for 3-4 minutes, rotating it so that all sides are seared.
Once the meat has browned, reduce the heat to medium-low, remove the roast from the pan and place it on a cutting board or platter. To the dutch oven, add the olive oil and vegetables. For 5-6 minutes, sauté the veggies so that they soften and brown a bit.
The next step is to harness the flavor from sautéeing the vegetables and searing the meat. Put a cup of beef broth in the dutch oven to deglaze the brown bits stuck to the bottom. Use a wooden spoon or spatula to scrape all of the “liquid gold” from the pot.
Add the brown sugar and any additional herbs and spices you wish, such as rosemary or salt and pepper.
Place the roast atop the vegetables in the dutch oven. Cover with a tight-fitting lid, and bake for about 20 minutes per pound at 275 degrees F. Be sure to check the doneness with an instant read thermometer. Rare: 130°F - Medium-Rare: 135°F - Medium: 145°F - Well-Done: 160°F. The temperature will rise 5–10 degrees as it rests.
Once the desired temperature is reached, remove the roast from the oven and let it rest for 15 minutes before slicing.
If you wish, make a gravy. Transfer the roast and vegetables to a large serving platter. Put the Dutch oven back on the stove over medium heat, and whisk in 1-2 tablespoons of flour. Continue whisking until a gravy forms.