Preheat your oven to 425°F (220°C). Line a large baking sheet with parchment paper for easy cleanup.
In a large bowl, combine the cubed sweet potatoes with melted butter, olive oil, minced garlic, rosemary, thyme, sea salt, and black pepper. Toss everything together until the sweet potatoes are well-coated.
Stir in the lemon zest and lemon juice for an extra zing. Ensure all pieces of sweet potato are evenly seasoned.
Spread the sweet potatoes in a single layer on the prepared baking sheet. Make sure they are not overcrowded, which helps with roasting.
Roast in the preheated oven for 25-30 minutes, flipping halfway through to ensure even browning. Cook until the sweet potatoes are tender and golden brown at the edges.
Once roasted, remove the sweet potatoes from the oven. If desired, sprinkle with fresh parsley before serving.
Serve warm as a delicious side dish for dinner or a hearty addition to a salad!