Step 1Preheat oven to 450°. Bring a large pot of water to a boil over high heat. Add potatoes and 2 teaspoons salt. Boil until fork-tender, about 15 minutes. Drain and let cool until cool enough to handle.
Step 2Pat potatoes dry with paper towels and transfer to a large bowl. Add olive oil and 3/4 teaspoon salt, then toss to coat. Spread potatoes on a large rimmed baking sheet. Using a glass or measuring cup, smash potatoes until about 1/4" thick.
Step 3Roast 20 minutes. Remove from oven and brush tops with chili oil, then continue to roast until crispy, about 5 minutes more.
Step 4Arrange potatoes on a platter. Garnish with scallions and serve with more chili oil alongside.
