Begin by chopping the red onion, mincing the garlic, halving the cherry tomatoes, and rinsing the cannellini beans. Make sure your halibut fillets are thawed if previously frozen. Season both sides of the halibut fillets with salt and freshly ground black pepper.
In a large skillet, heat the olive oil over medium-high heat. Once the oil is shimmering, gently place the halibut fillets in the skillet. Sear for about 4-5 minutes on one side, allowing a golden crust to form.
Carefully flip the halibut fillets using a spatula. Add the butter to the skillet and let it melt, spooning the melted butter over the fish. Cook for another 4-5 minutes, or until the halibut is cooked through and flakes easily with a fork. Remove the fish from the skillet and set aside.
In the same skillet, add the chopped red onion and sauté for 2-3 minutes until softened. Then, add the minced garlic, rosemary, and thyme, stirring for about 1 minute until fragrant.
Next, add the halved cherry tomatoes, chicken broth, and cannellini beans to the skillet. Stir well, allowing the mixture to simmer for about 4-5 minutes. Add the fresh spinach and stir until wilted. Finally, drizzle in the lemon juice and toss in the green olives and red pepper flakes.
Return the seared halibut fillets to the skillet, nestling them amongst the vegetables. Let everything heat through for another minute or two. Serve the Pan-Seared Halibut with Vegetables on a platter, spooning the vegetable mixture over the fish for a beautiful presentation.
