Mackerel Croquettes with Potatoes and Spinach

Ingredients

• 500 g Potatoes (peeled and cut into cubes)
• 1 Sweet onion (peeled and diced)
• 30 g Butter (to sauté the onion)
• 15 ml Whole grain mustard (one tablespoon)
• 2.5 ml Turmeric powder (½ teaspoon)
• 2.5 ml Ground cumin (½ teaspoon)
• 2.5 ml Sweet paprika (½ teaspoon)
• 100 g Fresh spinach leaves (washed)
• 30 g Fresh parsley (chopped, about 2 tablespoons)
• 200 g Grilled smoked mackerel fillets (coarsely crumbled)
• 2 Eggs (1 for the batter, 1 beaten for the coating)
• 100 g Breadcrumbs (preferably panko for extra crunch)
• à goût Salt
• à goût Freshly ground black pepper
• 200 ml Frying oil (sunflower or peanut) (for pan-frying)

Instructions

1. Cooking the potatoes

   Peel the potatoes, cut them into uniformly sized cubes and place them in a pot of boiling salted water. Cook until very tender (about 15 minutes).

   Time: PT15M

   Temperature: 100°C

2. Mashing the potatoes

   Drain the potatoes then mash them into a smooth purée in the same bowl or a large mixing bowl.

   Time: PT5M

3. Sauté the onion

   Melt the butter in a pan over medium heat, add the diced sweet onion and cook 3 to 4 minutes until translucent.

   Time: PT4M

   Temperature: 180°C

4. Add mustard, spices and spinach

   Stir in the whole grain mustard, turmeric, cumin and paprika into the pan. Add the spinach leaves and cook 2 minutes until just wilted.

   Time: PT2M

   Temperature: 180°C

5. Mix with the potatoes

   Transfer the onion‑spice‑spinach mixture into the mashed potatoes, add the chopped parsley and mix well. Let cool at room temperature for 10 minutes.

   Time: PT10M

6. Incorporate the mackerel and egg

   Add the coarsely crumbled smoked mackerel, one whole egg, salt and pepper. Mix until a homogeneous dough forms.

   Time: PT5M

7. Shape and refrigerate the croquettes

   With lightly floured hands, form balls then flatten into patties about 8 cm in diameter. Place on a plate, cover with plastic wrap and refrigerate for 30 minutes to firm up the dough.

   Time: PT30M

8. Prepare the coating

   Beat the second egg in a small bowl. Pour the breadcrumbs onto a flat plate.

   Time: PT2M

9. Coat the croquettes

   Dip each chilled croquette in the beaten egg, then roll it in the breadcrumbs, pressing lightly to adhere.

   Time: PT5M

10. Heat the oil

    Pour the frying oil into the pan and heat over medium‑high heat until it reaches about 180°C (when a small breadcrumb sizzles immediately).

    Time: PT5M

    Temperature: 180°C

11. Fry the croquettes

    Gently place the croquettes into the hot oil. Fry for 3 minutes, turning them halfway through, until golden and very crispy.

    Time: PT3M

    Temperature: 180°C

12. Drain and serve

    Remove the croquettes with a slotted spoon, place them on paper towels to remove excess oil. Serve immediately with tartar sauce or a lemon mayonnaise.

    Time: PT1M

Nutrition Facts

Calories

370

Protein

20 g

Carbohydrates

30 g

Fat

15 g

Fiber

3 g

Ingredient Substitutions

• Instead of Potatoes: Sweet potatoes
• Instead of Sweet onion: Shallot
• Instead of Butter: Olive oil
• Instead of Whole grain mustard: Dijon mustard
• Instead of Turmeric powder: Paprika
• Instead of Ground cumin: Ground coriander
• Instead of Sweet paprika: Mild chili pepper
• Instead of Fresh spinach leaves: Chopped spinach
• Instead of Fresh parsley: Chives
• Instead of Grilled smoked mackerel fillets: Canned tuna, Sardines
• Instead of Eggs: Flax egg (for vegan version)
• Instead of Breadcrumbs: Crushed dry biscuits
• Instead of Salt: Fleur de sel
• Instead of Freshly ground black pepper: White pepper
• Instead of Frying oil (sunflower or peanut): Light olive oil

Equipment Needed

• Saucepan
• Colander
• Frying pan
• Wooden spatula
• Mixing bowl
• Cutting board
• Chef's knife
• Paper towels
• Plastic wrap or lid
• Kitchen scale (optional)
• Measuring spoon (optional)
• Whisk or fork (optional)

Critical Steps — Do Not Skip

• Cooking the potatoes until tender
• Refrigerating the dough for 30 minutes
• Heating the oil to 180°C before frying
• Frying the croquettes until golden

Chef Tips from the Video

• Use flat‑leaf parsley, chopped, for a brighter color.
• Replace panko breadcrumbs with homemade toasted breadcrumbs for a more rustic flavor.
• Serve with a small arugula and lemon salad to balance the richness.

Troubleshooting

Storage

Refrigerator: Store cooked croquettes in an airtight container for 2 to 3 days.

Freezer: Breaded raw croquettes can be frozen for 1 month; fry directly from frozen, adding 1‑2 minutes cooking time.

Room temperature: Do not leave at room temperature for more than 2 hours.

Make-Ahead Tips

• Prepare the croquette dough and refrigerate up to 24 h before cooking.
• Breaded croquettes can be frozen raw and fried directly from the freezer.