Preheat the oven to 375°F (190°C) and grease a 9x13-inch baking dish with olive oil or unsalted butter.

Peel and cube sweet potatoes into ½-inch pieces, par-boil in boiling water for 10 minutes, or roast for 25 minutes until caramelized.

Sauté washed spinach in a large skillet with olive oil over medium heat for 3-5 minutes until wilted. Drain excess water and chop.

In the same skillet, add diced yellow onion, sauté for 4-5 minutes until soft, then add minced garlic and cook for another minute.

Combine chopped spinach with sautéed onion and garlic, add half of the shredded cheese blend, thyme, smoked paprika, salt, and pepper.

In another bowl, whisk together eggs and whole milk or half-and-half, add remaining thyme, smoked paprika, nutmeg, salt, and pepper.

Layer half of the cooked sweet potatoes in the greased dish, add spinach mixture, then the remaining sweet potatoes, and finally pour the egg mixture.

Optional: Mix panko breadcrumbs with melted butter and sprinkle over the bake.

Bake in preheated oven for 40-50 minutes until golden brown and custard is set.

Let the bake rest for 10-15 minutes before serving.