Best Fish with Fennel

Here is my go-to fish with fennel recipe, combining fresh white fish fillets with sweet, crisp fennel, a handful of herbs, and a splash of white wine for extra flavor.

This dish has become my weeknight dinner hero when I want something light but satisfying. I often make extra fennel because my kids surprisingly love its mild licorice taste, and the leftovers are great in salads the next day.

What Kind of White Fish Should I Use?

For this recipe, you’ve got plenty of good options when it comes to white fish. Cod, halibut, or haddock would all work great here – they’re mild-tasting fish that won’t overpower the delicate fennel flavor. If you’re shopping at the seafood counter, look for fillets that are firm to the touch and have a fresh, clean smell (there shouldn’t be any strong fishy odor). For the best results, choose fillets that are similar in thickness so they’ll cook evenly. If you’re working with frozen fish, just make sure it’s completely thawed in the refrigerator before cooking, and pat it dry with paper towels to remove any excess moisture.

Options for Substitutions

This fish recipe is pretty adaptable – here’s what you can swap if needed:

• Fennel bulb: Since fennel gives this dish its signature flavor, it’s best not to skip it. However, if you absolutely must, you could use celery plus a pinch of fennel seeds to get a similar taste profile.
• Japanese sweet potatoes: Regular sweet potatoes work perfectly fine here. You can also use regular potatoes or even cauliflower if you’re looking for a lower-carb option.
• White fish fillets: Any mild white fish works well – try cod, halibut, haddock, or tilapia. Just adjust cooking time based on the thickness of your fillets.
• Fresh lemon juice: While fresh is best, you can use bottled lemon juice in a pinch. Use about 3 tablespoons instead of 1/4 cup as bottled tends to be more concentrated.
• Thyme: You can swap thyme with other herbs like oregano or herbs de Provence. If using dried instead of fresh, use 1/3 of the amount.
• Parsley: Feel free to use cilantro or fresh dill instead. If you don’t have fresh herbs, you can skip the garnish altogether.

Watch Out for These Mistakes While Cooking

The biggest challenge when cooking fish with fennel is timing – fish can quickly go from perfectly flaky to overcooked and dry in just a matter of minutes, so it’s crucial to check for doneness when the flesh turns opaque and flakes easily with a fork. Adding the fish to the pan at the wrong time is another common mistake – make sure to cook your fennel and sweet potatoes first until they’re almost tender, then add the fish on top to ensure everything finishes cooking at the same time. To prevent the garlic from burning and turning bitter, add it halfway through cooking the vegetables rather than at the beginning, and don’t forget to pat your fish dry with paper towels before cooking – excess moisture will prevent that nice golden crust from forming. For the best flavor development, let the cooked dish rest for 5 minutes before serving, allowing the flavors to meld together while the fish stays perfectly moist.

What to Serve With Fish and Fennel?

Since this dish already includes sweet potatoes, you’ve got your main protein and a starchy side covered – but there are still some great ways to round out the meal! A simple green vegetable like steamed asparagus or sautéed green beans would work perfectly alongside the delicate fish and aromatic fennel. For a light start to the meal, try serving a crisp arugula salad dressed with just olive oil and lemon juice, which echoes the citrus notes in the main dish. If you’re feeling like you want something extra, a scoop of fluffy couscous or quinoa can help soak up all those tasty pan juices.

Storage Instructions

Keep Fresh: Once cooled, place your leftover fish and fennel in an airtight container and pop it in the fridge. The dish will stay good for up to 2 days. Keep in mind that fish is best enjoyed fresh, so try to eat it sooner rather than later!

Prep Ahead: Want to get a head start? You can slice the fennel, cube the potatoes, and crush the garlic up to 24 hours in advance. Store these prepped ingredients in separate containers in the fridge. Just remember to toss the potatoes in a bit of lemon juice to prevent browning.

Serve Again: When you’re ready to enjoy your leftovers, gently warm them in a covered pan over low heat until just heated through. Try not to overheat, as this can make the fish dry and rubbery. A splash of olive oil while reheating helps keep everything moist.

Preparation Time	15-20 minutes
Cooking Time	35-40 minutes
Total Time	50-60 minutes
Level of Difficulty	Medium

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 800-900
• Protein: 50-60 g
• Fat: 40-50 g
• Carbohydrates: 70-80 g

Ingredients

• 1 large fennel bulb, sliced
• 1 pound japanese sweet potatoes, peeled and cubed
• 3 large garlic cloves, crushed
• 3 tablespoons olive oil
• 1/4 cup lemon juice, freshly squeezed
• 1 teaspoon sea salt
• 1 teaspoon thyme (fresh or dried)
• 1 pound white fish fillets
• 1 lemon, sliced
• 1/4 cup parsley, separated

Step 1: Prepare the Marinade

Preheat your oven to 450°F (232°C).

In a small bowl, mix together crushed garlic, olive oil, lemon juice, sea salt, and thyme to create a flavorful marinade.

Step 2: Marinate the Vegetables

Add the cubed sweet potatoes and sliced fennel to a large cast iron skillet or a sheet pan.

Drizzle with one-third of the marinade.

Use your hands to massage the marinade into the fennel and sweet potatoes to ensure they are well coated.

Step 3: Marinate the Fish

Place the fish in a large bowl and drizzle the remaining marinade over it.

Allow the fish to soak in the flavors while the vegetables start cooking.

Step 4: Roast the Vegetables

Put the skillet or sheet pan with the marinated sweet potatoes and fennel into the preheated oven.

Bake for 20 minutes until they start to brown and caramelize on one side.

Step 5: Cook the Fish with Vegetables

After 20 minutes, carefully flip or stir the vegetables.

They should be nicely browned and caramelized on one side.

Top the vegetables with the marinated fish and lemon slices, making sure to include all the juices from the bowl.

Sprinkle half of the fresh parsley over the top.

Return the pan to the oven for another 15-20 minutes until the fish is thoroughly cooked.

Step 6: Garnish and Serve

Once cooked, remove the pan from the oven and garnish with the remaining fresh parsley.

Serve the dish hot, enjoying the blend of roasted vegetables, flavorful fish, and fresh herbs.