This recipe is ideal for a weeknight meal or as a side dish for entertaining. It's hearty and full of natural sweetness and flavor. Be sure to keep the stacked slices of sweet potatoes tightly packed as you place them in the baking dish so they do not bend or fold. This will ensure even baking.
Preheat the oven to 400 degrees F. Prepare a large baking dish with olive oil and set aside.
Using a mandoline, thinly slice the sweet potatoes and stack them vertically in a bowl or measuring cup until you're ready to transfer them to the prepared baking dish. When the slicing is complete, transfer the stacks of sweet potatoes into the baking dish starting with the outside and working your way inside. If you're using a variety of colors of sweet potatoes, you may want to alternate them as I have in the photos above.
In a small bowl, combine the oil with the cayenne pepper, ginger and cumin. Use a brush to brush the sweet potatoes so the oil seeps down into the cracks in between each potato. Transfer to the oven and bake for 45-50 minutes or until the sweet potatoes are very tender. Check on the sweet potatoes half way through to ensure they are not drying out. Brush more oil onto the sweet potatoes, as needed.
Meanwhile toast the sesame seeds in a large dry skillet over medium heat for 2 minutes or until golden brown and fragrant. Remove from the heat and set aside.
Remove the tian from the oven; set aside for 5 minutes to cool before serving. Sprinkle with the sesame seeds and caraway seeds. Add a pinch of sea salt and pepper, to taste and garnish with fresh oregano. Serve warm.
Store leftovers in a sealed container in the refrigerator for up to 4 days or in the freezer for up to 2 months. Bring to room temperature before serving.