Preheat oven to 400°F. Chop potatoes into bite-sized chunks.
Slice the smoked sausage into rounds or half-moons.
In a large bowl, toss the potatoes and sausage with ranch seasoning, olive oil, salt, and pepper.
Spread the mixture on a foil-lined baking sheet or casserole dish. Bake for approx 40 minutes, stirring halfway. For extra crispiness, broil for 1 minute at the end.
Sprinkle cheese on top and bake until melted, about 5 more minutes.
Top with green onions, if using, and serve hot.
Notes
Feel free to customize the ingredients; you can use different types of sausage or seasonings based on your preference.