If using wooden skewers, soak in a large shallow dish in water so that they do not catch fire on the grill. If using metal skewers, no extra preparation is necessary.
Pre-cook the potatoes until easily pierced with a fork, but not falling apart. To cook in the Instant Pot, use a steamer basket insert, 1 cup of water, and cook for 10 minutes on manual. Quick-release and allow to cool. Alternatively, boil potatoes in a stock pot full of water for 15-20 minutes, or until soft but not falling apart, then drain through a colander and allow to cool.
As the potatoes cook, cube and season your steak by cutting into one-inch cubes with a large chef's knife, and tossing with the Steak Rub.
Once potatoes are cool enough to handle comfortably, cut in half if needed to make them bite-sized, and toss with olive oil and crushed garlic.
Thread potatoes and steak cubes in a pattern on the skewers. Cover and place in the refrigerator until ready to grill- this can be done in the morning and grilled in the evening if desired.