Preheat grill to medium-high. Soak skewers for 20 minutes.
Toss steak with 2 tbsp. olive oil and 1 tbsp. rosemary. Season with salt and pepper to taste. Let marinate while you prepare the potatoes.
Place potatoes in a large microwave-safe bowl. Cover and microwave on until just tender, about 6-8 minutes. Set aside until cool enough to handle. Toss with 2 tbsp. olive oil, 1 tbsp. rosemary and mustard. Season with salt and pepper to taste.
Thread steak and potatoes onto skewers. Grill, turning occasionally, until steak is medium, 8 minutes.
Serve with steak sauce, if desired.
Recipe by 5* trending recipes with videos at https://food.theffeed.com/2020/05/14/steak-and-potatoes-on-a-stick/