Preheat oven to 425 and line baking sheet with parchment paper
Wash and dry each sweet potato. Pierce all over with a fork, then lightly brush with olive oil, sprinkle with Maldon sea salt, and place directly onto baking sheet.
Bake for 45-50 minutes, or until fork tender. Let cool for 10-15 minutes then split open with a knife and rub the insides with a little butter.
To prepare spinach, heat butter in nonstick skillet over medium heat. Add spinach & garlic, and season with salt and pepper. Cook until wilted.