Preheat oven to 375 degrees.
Coat the roast with salt and pepper. Heat the oil in a large pan or Dutch oven over medium-high heat. When hot, add the roast, browning on all sides, for a total of about 8 minutes.
Meanwhile, toss the sweet potatoes with the garlic and olive oil. Set aside.
Place the roast in a large roasting pan and roast in oven for 20 minutes per pound (more or less), checking temperature for desired doneness.
Add sweet potatoes to roasting pan, encircling the roast during the last 45 minutes of cooking time. Season potatoes with sea salt. Toss once during cooking time.
Meanwhile, in a large pot fitted with a steamer insert, bring about 1 inch of water to a boil. Add the broccoli and steam for 5-7 minutes or until desired tenderness is reached.
Allow roast to rest for at least 15 minutes before slicing. Sprinkle sweet potatoes with chopped cilantro before serving.