Begin by melting butter in the microwave until liquid. In a large bowl, mix the melted butter with olive oil, then cube the russet potatoes and slice the onion. Toss everything together with dry ranch seasoning until the potatoes and onion are evenly coated.

Preheat your grill to medium-high heat, reaching around 400°F. Cut four sheets of aluminum foil, each about 12 inches long. Spray the centers of these sheets with cooking spray to prevent sticking. Divide the potato mixture evenly among the sheets, then carefully fold and seal them tightly.

Place the foil packs directly onto the hot grill. Cook them for 20 to 25 minutes, turning each pack every 5 minutes to ensure even cooking.

Once the potatoes are tender, open the foil packs carefully to avoid steam. Sprinkle grated sharp cheddar cheese and precooked bacon pieces on top of each pack.

Close them again and return the packs to the grill for an additional 5 minutes, allowing the cheese to melt beautifully over your flavorful Grilled Potatoes in Foil.

After the cheese has melted, remove the foil packs from the grill. Open them up and add optional toppings like sour cream and fresh parsley. Serve hot.