Step 1
Preheat the oven to 400 degrees F (200 degrees C). Line a baking sheet with parchment paper.
Step 2
Rinse potatoes in a colander to remove excess starch. Drain.
Step 3
Place potatoes in a large microwave-safe bowl; add 1 tablespoon oil and salt and toss to coat. Cover and microwave on high for 4 minutes. Stir cover again and microwave until fork-tender about 2 minutes more. Drain well.
Step 4
Spread potatoes on the lined baking sheet. Drizzle with remaining oil and toss to coat. Spread out in an even layer.
Step 5
Roast in the preheated oven until golden brown about 20 minutes. Stir and continue roasting until evenly browned about 5 minutes more.
Step 6
Meanwhile combine butter harissa cilantro and lemon zest in the same bowl. Mash together with a fork. Taste and season with salt if needed. Add potatoes to the harissa butter and toss. Serve immediately.