Preheat oven to 200F.
Season the steaks on both sides and place on a foil-lined baking sheet.
Bake until the internal temperature reaches about 110F.
Meanwhile, preheat a cast iron pan over medium-high heat as the steaks are approaching 110F internal temperature. Use a BBQ or an oven-safe meat thermometer. There is no other good way here.
Remove the steaks from the oven and immediately place on the hot pan. Sear on both sides until nicely browned and the desired target temperature is achieved. Remember, the temperature will keep rising after you remove the steaks from the pan so you have to account for that. Here is a quick reference sheet I use:Rare - Remove from the pan at 120°F, 125°F Final Cooked TempMedium Rare - Remove from the pan at 130°F, 135°F Final Cooked TempMedium - Remove from the pan at 140°F, 145°F Final Cooked TempMedium Well - Remove from the pan at 150°F, 155°F Final Cooked TempWell Done - Remove from the pan at 160°F, 165°F Final Cooked Temp
Keep a close eye on the steaks if you used brown sugar as they will brown faster and you may have to flip them a few times to prevent burning.
Remove the steaks from the pan and place on a serving platter. Cover with foil and let rest for 5-10 minutes before serving.
I recommend serving tri-tip steaks with homemade red wine sauce and your favorite side dish.