Make 4 parchment paper cones and place them in 4 cups.
Heat the oil, along with the thyme, garlic, rosemary and sage, in a heavy-bottomed pot over medium heat to 365 degrees F. The herbs should be nice and crackly at this stage. Using a slotted spoon, transfer the herbs and garlic to a paper towel-lined plate. Set aside.
Using a mandoline, cut the potatoes into matchsticks and place in a large bowl of ice water. Soak for a few minutes, then rinse with cold water until the water runs clear. Drain the matchsticks and pat dry in a kitchen towel to remove as much water as possible. Fry in small batches until golden and crispy, 2 to 3 minutes. Transfer to the paper cones and season with some Cajun Spice Mix. Peel the fried garlic cloves and sprinkle them and the fried herbs over the potatoes.
Cajun Seasoning:
Mix together the garlic powder, onion powder, smoked paprika, cayenne, salt and pepper in a small bowl.