Preheat oven to 425 degrees F (218 C) and line 1 large baking sheet with parchment paper. NOTE: If doubling/multiplying the recipe, be sure not to crowd the baking sheet or add too many potatoes to the oven at once or they will have a hard time roasting and will steam instead, producing mushier, less browned / crispy potatoes.
Add potatoes to the baking sheet and drizzle with avocado oil. The potatoes should be coated but not soaking in oil. Then add salt, pepper, and rosemary (optional) and toss well to combine.
Roast until golden brown and crispy, or about 20-25 minutes. You'll know they're done when golden brown on the bottom and edges and tender in the center.
Enjoy immediately with sides and sauces of choice. We prefer ketchup or hot sauce. Aioli would also be tasty.
Store cooled leftovers in the refrigerator up to 3-4 days (not freezer friendly). Reheat in the microwave or — our preference — on a cast iron skillet over medium heat.
*Nutrition information is a rough estimate calculated with the lesser amount of avocado oil and without optional ingredients.