Preheat your oven to 400°F (200°C). Toss the diced sweet potatoes with half of the olive oil, cinnamon, smoked paprika, and a pinch of salt and pepper. Spread them out evenly on a baking sheet lined with parchment paper.
Roast the sweet potatoes in the oven for about 20-25 minutes, flipping halfway through, until they are tender and golden around the edges.
While the sweet potatoes roast, heat the remaining olive oil in a large skillet over medium heat. Add the sliced red onion and red bell pepper, and sauté for 5-7 minutes until they soften and develop a slight char.
Once the sweet potatoes are roasted, add them to the skillet with the sautéed vegetables. Cook everything together for another 5 minutes, stirring occasionally, until the sweet potatoes are crispy at the edges and well combined with the veggies.
Season the hash with additional salt and pepper to taste. Give it a final stir and let it sit for a minute so flavors meld.
Spoon the hot sweet potato hash onto plates, garnish with fresh herbs if desired, and enjoy the hearty, crisp-tender texture and aromatic flavors.