Hamburger Hash

Bahan-bahan (4 porsi)

• 1 pound Yukon gold potatoes (or red potatoes, cut into ½-inch cubes)
• 1 tablespoon olive oil
• 3 tablespoons butter (divided)
• 1 medium onion (diced)
• 1 pound lean ground beef
• 2 teaspoons steak spice (*see note)
• 2 cloves garlic (minced)
• chopped fresh parsley (optional)