In a mixing bowl, combine the olive oil, lemon juice, garlic powder, Spike Seasoning, dried basil, dried oregano, onion powder, dried sage, and black pepper. Whisk together until all ingredients are well incorporated.
Place the chicken thighs in a resealable plastic bag or a shallow dish. Pour the marinade over the chicken, ensuring each piece is well coated. Seal the bag or cover the dish, and refrigerate for at least 1 hour, or up to 8 hours for maximum flavor.
If grilling, preheat your grill to medium-high heat. If roasting, preheat your oven to 425°F (220°C).
For grilling, remove the chicken thighs from the marinade and place them skin-side down on the grill. Cook for about 7-8 minutes on each side, or until the internal temperature reaches 165°F (75°C). For roasting, place the chicken thighs skin-side up on a baking sheet and roast for 35-40 minutes, or until fully cooked.
Once cooked, remove the chicken thighs from the heat and let them rest for about 5 minutes. This allows the juices to redistribute throughout the meat. Serve with your favorite sides and enjoy!