Preheat the oven to 400 degrees F. Line a baking sheet with foil. Wash and dry the potatoes. Cut in half lengthwise and add them to a large bowl.
Add the pesto and lemon juice to the bowl of potatoes and stir until every potato is coated. Sprinkle with salt and pepper.
Pour the potatoes onto the baking sheet and spread them into an even single layer. Roast in a preheated oven for 20-25 minutes, or until the potatoes are fork tender.