Preheat your oven to 425°F and line a rimmed baking sheet with parchment paper.
Pat the chicken drumsticks thoroughly dry with paper towels to ensure the skin becomes extra crispy during roasting.
In a small bowl, whisk together half of the olive oil with the sea salt, black pepper, dried oregano, and garlic powder.
Rub the herb-oil mixture evenly over the chicken drumsticks and arrange them on the prepared baking sheet.
Roast the chicken for 25 to 30 minutes, flipping once halfway through, until the skin is golden brown and the internal temperature reaches 165°F.
While the chicken finishes roasting, mince the fresh garlic cloves.
Heat the remaining olive oil in a large skillet over medium heat.
Add the minced garlic and red pepper flakes to the skillet, sautéing for about 1 minute until highly fragrant.
Add the chopped kale to the skillet and cook for 3 to 5 minutes, tossing frequently until the leaves are wilted and tender.
Remove the kale from the heat, stir in the fresh lemon juice, and serve immediately alongside the roasted chicken drumsticks.