Step 1

Preheat the oven to 450°F.

Step 2

Fill a large pot three-​quarters full with water. Add 1 tsp. salt and the potatoes and bring to a boil over high heat. Reduce the heat to medium-​low and simmer until a knife easily pierces the largest potato, 12 to 15 minutes. Drain the potatoes in a colander and set aside to cool.

Step 3

Toast the coriander seeds in a small, dry pan over medium heat for about 1 minute. Add the cumin seeds and fennel seeds and toast, shaking the pan gently so that the seeds toast evenly and do not burn, until all the spices are fragrant, about 1 more minute. Remove from the heat and, when cool enough to handle, grind in a spice grinder or coffee grinder, or with a mortar and pestle. Set aside.

Step 4

Once the potatoes are dry and cool enough to handle, smash them lightly with the bottom of a small frying pan, flattening them. Do not break them up completely.

Step 5

In a large mixing bowl, toss the smashed potatoes with the oil, lime zest, toasted spice mixture, cayenne, cinnamon, and remaining 1 tsp. salt until nicely coated. Arrange in a single layer on a sheet pan and roast in the oven for 6 to 8 minutes, until the potatoes are crispy and golden brown on the outside. Transfer the potatoes to a large platter for serving, then top with a squeeze of lime juice, a sprinkle of chopped cilantro, and a few pinches of flaky sea salt.