Begin by preheating your oven to 225°F (110°C) and gather all necessary ingredients.
In a small bowl, combine salt, black pepper, paprika, garlic powder, cayenne pepper, and both dried and fresh rosemary to create a flavorful spice blend.
Place the tri-tip roast in a baking dish and generously rub the spice mixture all over, ensuring both sides are well coated.
Transfer the dish to the preheated oven and roast the meat until it reaches an internal temperature of 130°F (54°C) for medium-rare, which should take approximately 1.5 to 2 hours. Remember to flip the tri-tip halfway through cooking for even browning.
Once done, cover the pan with aluminum foil and allow the meat to rest for about 20 minutes. This helps the juices redistribute.
Remove the roast from the pan and place it on a cutting board. Cut it into two sections where the grain changes direction, then slice against the grain for the most tender pieces.
To enhance the flavor, mix some beef broth with the pan drippings and drizzle it over the sliced tri-tip before serving.