1-Prepare and marinate the steak and mushrooms: Cut ribeye into 16 equal 1.5-inch pieces, place steak and 8 baby bella mushrooms in a gallon zip-top bag.

2-Whisk the marinade: Whisk soy sauce, ketchup, vegetable oil, white vinegar, brown sugar, and garlic powder until sugar dissolves; pour over steak and mushrooms, seal, massage, and let sit at room temperature 30 minutes (or refrigerate up to 2 hours).

3-Par-boil the potatoes: Boil potatoes covered with cold water for 5–7 minutes until just fork-tender; drain and cool slightly.

4-Assemble the kabobs: Thread skewers in repeating order: steak, potato, steak, mushroom, leaving space between pieces; each skewer gets two pieces of each.

5-Grill to perfection: Preheat grill to medium-high (400°F), oil grates, grill 5–6 minutes per side, flipping every 3 minutes, until internal temp 135°F (medium-rare), about 10–12 minutes total; rest 5 minutes.