Preheat your oven to 400°F and line a baking sheet with parchment paper.
Peel the sweet potato and cut it into 1/2-inch cubes.
Toss the sweet potato cubes with olive oil, 0.25 tsp sea salt, and 0.125 tsp black pepper on the prepared baking sheet.
Roast the sweet potatoes for 20 to 25 minutes, tossing halfway through, until they are tender and slightly browned.
While the potatoes roast, thinly slice the yellow onion and mince the garlic cloves.
Pat the steak tips dry with a paper towel and season them with the dried rosemary and the remaining sea salt and black pepper.
Heat a large cast-iron skillet over medium-high heat and add 0.5 tbsp of ghee.
Sear the steak tips for 2 to 3 minutes per side until a golden crust forms, then remove them from the skillet and set aside.
Lower the heat to medium, add the remaining 0.5 tbsp of ghee and the sliced onions, sautéing for 5 to 7 minutes until soft and caramelized.
Stir in the minced garlic for 30 seconds until fragrant, return the steak tips to the pan to warm through, and serve alongside the roasted sweet potatoes.