Oven-baked mackerel

Ingredients

• 3mackerel
• 2potatoes
• 1onion
• 4green peppers
• 2 clovesgarlic
• to tasteparsley
• to tastesalt
• to tasteblack pepper
• a generous drizzleolive oil

Instructions

1. 1

   Preheat the oven

   Heat the oven to 180°C, using both the top and bottom heating elements.

2. 2

   Cook the peppers

   Wash the peppers and slice them into strips. Season them in a frying pan and cook over a low heat for 15 minutes.

3. 3

   Slice the vegetables

   Cut the potatoes into slices or batons, and slice the onion into thin strips.

4. 4

   Bake the vegetables

   Arrange the potatoes and onion on an oven tray, drizzle generously with olive oil and place the tray in the oven.

5. 5

   Add the mackerel

   When the potatoes and onion are nearly cooked, remove the tray from the oven and lay the mackerel fillets or pieces on top.

6. 6

   Bake the fish

   Return the tray to the oven and cook the mackerel for about 10 minutes.

7. 7

   Prepare the garlic

   Meanwhile, peel and thinly slice the garlic. Warm a frying pan over a medium heat and briefly cook the garlic until it starts to turn golden.

8. 8

   Finish the dish

   Remove the fish from the oven when it is ready and pour the garlic dressing over it. Add the peppers to the tray and scatter a little parsley over the top.

What is oven-baked mackerel?

Mackerel is a familiar fish in Spanish cooking, often served simply with vegetables and olive oil. This version pairs it with potatoes, onion and green peppers for a hearty tray-baked meal.

The method cooks the vegetables first, then adds the fish near the end. That helps the potatoes soften while keeping the mackerel from spending too long in the oven.

Nutrition and macros by portion

The nutrition label shows one serving as written: 330 calories, 22g protein, 39g carbs, 11g fat.

The potatoes provide most of the carbohydrates, while mackerel contributes much of the protein and fat. To balance the plate, serve a portion with extra salad or another non-starchy vegetable.

Build the vegetable base

Potatoes and onion: slice them evenly so they cook at a similar pace, then spread them across the tray with olive oil.

Green peppers: cook them gently in a frying pan for 15 minutes before adding them to the finished tray. This gives them time to soften without relying on the fish’s shorter baking time.

Get the mackerel ready

Fillets or pieces: the method allows for either, so use mackerel prepared in the form you have. Arrange it in a single layer over the nearly cooked vegetables.

Timing: bake the fish for about 10 minutes, as directed. Its thickness and starting temperature can affect how quickly it cooks, so check that it is ready before serving.

Make the garlic dressing

Thin slices: cut the garlic evenly so the pieces colour at roughly the same rate. Cook it briefly over medium heat and take it off the heat as soon as it begins to turn golden.

Finish: pour the garlic over the cooked mackerel, then add the peppers and parsley. The dressing brings a savoury, aromatic finish to the fish and vegetables.

Serving and timing

The recipe gives a 15-minute cooking time for the peppers and about 10 minutes for the mackerel, but does not specify how long the potatoes and onion need in the oven. Use the stated cue—nearly cooked—before adding the fish.

Serve the mackerel straight from the tray with the potatoes, onion and peppers. A simple green salad can add a fresh contrast without competing with the garlic and fish.

Seasoning and texture

Season the peppers as they cook, and adjust the fish and vegetables to taste. Mackerel is naturally rich, so the parsley and peppers help keep the dish feeling balanced.

Avoid leaving the garlic until it becomes deep brown, as it can taste bitter. Golden is the cue to finish cooking it.

Recipe notes & tips

• Cut the potatoes into similarly sized slices or batons so they cook more evenly.
• Keep the peppers over a low heat while they cook for 15 minutes.
• Spread the potatoes and onion across the tray rather than piling them up.
• Add the mackerel only once the vegetables are nearly cooked.
• Watch the garlic closely and stop cooking it as soon as it starts to turn golden.
• Scatter the parsley over the dish just before serving.

Variations

• Add lemon: serve with lemon wedges for a bright, citrusy accent.
• Use smoked paprika: season the vegetables with a little for a warm, smoky note.
• Swap the herbs: use chopped fresh coriander instead of parsley.
• Add tomatoes: include sliced tomatoes on the tray with the potatoes and onion.
• Use red peppers: replace some or all of the green peppers for a sweeter flavour.

Common mistakes to avoid

• Adding the fish too early: it may overcook while the potatoes finish; wait until the vegetables are nearly cooked.
• Crowding the tray: the vegetables may cook unevenly; spread them out in a more even layer.
• Uneven potato slices: some pieces can stay firm while others soften; cut them to a similar size.
• Burning the garlic: it can turn bitter; cook it briefly and remove it as soon as it starts to colour.
• Skipping the pepper cooking stage: the peppers may not soften as intended; cook them gently for the full 15 minutes.

How to store

Refrigerate leftovers in a covered container and eat within 2 days. Reheat gently in the oven until hot throughout; take care not to overcook the mackerel.

Frequently asked questions