Preheat the oven to 400° F (200° C). Prepare 2 parchment paper-covered baking trays.
Peel and cube two of the sweet potatoes and place them on the trays. Sprinkle with avocado oil, salt and pepper, toss to cover and spread into a single layer. Leave the third sweet potato whole, just scrub it and prick with a fork, and place on one of the baking trays.
Roast the sweet potatoes for 20-30 minutes, until the cubed ones are soft and browned in places. Toss at half time. The whole sweet potato will take a little longer to bake. Cook it until it's easily pierced with a knife. Store the potatoes in an airtight container in the refrigerator.
Recipe by Golubka Kitchen at https://golubkakitchen.com/plant-based-meal-plan-mini-black-beans-sweet-potatoes-harissa/