Vivaneau Rouge Rôti avec Fenouil et Tomates (Red Snapper Baked with Fennel and Tomatoes)

Ingredients

• 3 plum tomatoes, cored and halved lengthwise
• 1 medium bulb fennel, trimmed, cut into 12 wedges
• 1 medium yellow onion, cut crosswise into 12″ slices
• 4 cloves garlic
• Kosher salt, to taste
• ¹⁄₂ cup fresh lemon juice
• ¹⁄₃ cup olive oil
• 1 tsp. lightly crushed coriander seeds
• 1 tsp. lightly crushed black peppercorns
• 1 tsp. dried thyme
• 2 bay leaves
• 2 (1-lb.) whole red snappers, cleaned and scaled
• Freshly ground black pepper, to taste
• 1 tbsp. finely chopped parsley
• Baguette slices, for serving