In a bowl, combine the olive oil, lemon juice, minced garlic, paprika, dried thyme (or fresh thyme leaves), salt, and pepper. Mix everything well to create a flavorful marinade.

Place the boneless chicken thighs in a resealable plastic bag or a shallow dish. Pour the marinade over the chicken, ensuring that each piece is coated evenly. Seal the bag or cover the dish with plastic wrap. Let the chicken marinate for at least 30 minutes in the refrigerator. For even better flavor, marinate for up to 4 hours or overnight.

Preheat your Ninja Foodi Grill to the grill function at medium-high heat (about 375°F or 190°C). If your grill has different temperature settings, aim for a medium-high heat.

Once the grill is hot and ready, remove the chicken from the marinade, allowing any excess to drip off. Place the chicken thighs onto the grill grates. Close the lid and grill for approximately 6-8 minutes per side or until the internal temperature of the chicken reaches 165°F (74°C) and the chicken is nicely browned and charred.

Carefully remove the grilled chicken thighs from the Ninja Foodi Grill and transfer them to a serving platter. Allow them to rest for a couple of minutes before serving. Garnish with fresh herbs or lemon slices if desired. Enjoy your delicious Ninja Foodi Grill Chicken Thighs!