Preheat the oven to 375 degrees. Coat a glass baking dish with olive oil cooking spray.
Prepare the fennel by discarding the thick outer layers of each bulb and slicing each into 4 equal slices.
Lay the pieces into the baking dish and drizzle with olive oil, then season with sea salt and freshly cracked pepper to taste.
Turn the fennel over and drizzle the other side with olive oil, then season with sea salt and freshly cracked pepper to taste.
Cook the fennel by putting the baking dish in the oven and roasting it for 30-35 minutes.
Flip the fennel over, then return to the oven and roast for another 30-35 minutes or until golden brown and tender.
Meanwhile, make the tapenade by combining the olives, parsley, olive oil, capers, vinegar, garlic, crushed pepper, and tarragon in a bowl. Season with sea salt and freshly cracked pepper to taste and toss to coat evenly. Set aside to allow the flavors to mingle while the fennel roasts.
Remove the fennel from the oven once it is golden brown and very tender.
To serve, arrange the fennel on a serving platter, then sprinkle with the olive tapenade, feta cheese, and fennel fronds.