Preheat the oven to 200°C. Cut the fennel into thin wedges and the zucchini into half-moons. Distribute them over a baking sheet, drizzle with half the olive oil, add the peeled and crushed garlic and some thyme, and season with salt and pepper. Roast for twenty minutes.
Pat the sea bass fillet dry and season the skin side with salt. Heat the remaining olive oil in a skillet until very hot and place the fish skin-side down in the pan. Press it lightly for the first few seconds so the skin stays flat and cook for three to four minutes until it's crispy. Flip the fish and immediately remove the pan from the heat; the residual heat will finish cooking it.
Fold the olives into the roasted vegetables and place the fish on top. Squeeze a few drops of lemon over it. White fish is a light yet complete protein source and the fennel provides a sweet, anise-like note that pairs well with the salty olives.