Heat oven to 425°F (220°C). Line a baking sheet with parchment paper. This keeps potatoes from sticking and helps crisp the edges evenly.

Boil the baby potatoes in a pot of salted water for 25 minutes until tender. They should pierce easily with a knife but not fall apart. This ensures they smash cleanly without turning mushy. Drain and let steam off for a few minutes.

Toss the smashed potatoes with olive oil, halved garlic, salt, pepper, and thyme. Make sure oil coats all surfaces and settles into cracks for maximum crispness.

Roast for 35 minutes, checking halfway through. The edges should turn golden brown and crisp, while the centers remain soft and tender.

Once roasted, squeeze softened garlic out of skins onto the potatoes. Drizzle with lemon juice, sprinkle with grated Parmesan, and top with fresh dill.

Serve hot for best texture. The edges are at their crispiest right out of the oven.