Add rinsed potatoes to a large pot and cover with water until just submerged. Bring to a boil over high heat. Then reduce to medium-high heat to achieve a low boil. Cook uncovered for 15-20 minutes or until tender and a knife easily slides in and out.
Prepare pesto by adding basil, garlic, nuts, lemon juice, and nutritional yeast to a food processor and blending to combine. Stream in 2-3 Tbsp olive oil a little at a time until a thick paste is formed. Taste and adjust flavor as needed. Transfer to a small serving dish and set aside.
Preheat the oven to 450°F and line a baking sheet with parchment paper. When the potatoes are soft and tender, place on the baking sheet and smash down with the bottom of a mason jar or cup.
Drizzle the potatoes with 1 1/2 Tbsp oil and season with a healthy pinch of salt and pepper. Roast for 20-25 minutes or until crispy and golden brown.
To serve, spoon the pesto over the potatoes. Garnish with fresh basil, parmesan, or additional pine nuts.
Serve and enjoy!