Place potatoes in a large saucepan and fill with cold water. Add a big pinch of salt. Bring to a boil over medium-high heat and boil for 20 minutes until softened, but not 100% cooked. They should be fork-tender but should not fall apart. Drain the potatoes and place on a clean kitchen towel. Pat them dry to get rid of any excess moisture.

Preheat the oven to 450 degrees. Line a rimmed baking sheet with parchment paper or a silicone baking mat.

Place par-boiled potatoes in a bowl and drizzle with 3 tablespoons olive oil and season with salt, pepper, and thyme. Use a spoon or your hands to toss the potatoes and make sure they are well coated with oil and seasonings. I like to season the potatoes whole, before smashing, to prevent them falling apart.

Place potatoes in a single layer on the prepared baking sheet. Spray the bottom of a mason jar, drinking glass or measuring up with non-stick spray or drizzle with oil. Using the bottom of whichever vessel you decided on, apply pressure in one swift motion to smash potatoes down to about 1/4-inch thickness.

After all of the potatoes are smashed, drizzle with an additional tablespoon of olive oil and hit them with another pinch of salt and pepper.

Roast at 450 degrees for 20-25 minutes until the potatoes are golden brown and achieve maximum crispiness. Sprinkle with more fresh thyme leaves if desired and serve hot with garlic parmesan aioli.