Cut the sweet potatoes in half, lengthwise.
Place one of the sweet potato halves on a cutting board and lay stainless steel straws, wooden spoons, or chopsticks on either side of the sweet potato (see the picture above in the post).
Make small, even slices on the sweet potatoes, as close together as you are able to, using the steel straws (or wooden spoons/chopsticks) to stop you from cutting all the way through the sweet potatoes.
Repeat with the other sweet potatoes.
Place the sweet potatoes on a parchment paper lined baking tray.
In a small bowl, add the extra virgin olive oil, thyme, sage, rosemary, salt, and pepper and stir to combine.
Brush the sweet potatoes with the olive oil/herb mixture.
Bake for 1 hour in a preheated oven at 400 degrees Fahrenheit, or until the bottoms of the sweet potatoes are dark golden brown but not burnt, pausing to baste the sweet potatoes with more of the oil mixture every 20 minutes.
Makes 8 servings of vegan hasselback sweet potatoes.