Recipe

Bonito Gratin with Mushrooms and Hard-Boiled Egg

Name: Bonito Gratin with Mushrooms and Hard-Boiled Egg
Prep time: 20 min
Cook time: 35 min
Total time: 60 min
Ingredients: 375 g canned tuna, drained weight; 3 eggs; 300 g fresh mushrooms; 1 small onion (about 100 g); 1 tablespoon olive oil; 20 g butter, and a little more to grease the dish; 25 g wheat flour; 400 ml milk; ¼ teaspoon salt; ¼ teaspoon ground black pepper; 2 tablespoons chopped parsley; Zest of ½ lemon (optional); 60 g grated melting cheese

Canned tuna with sautéed mushrooms, hard-boiled egg, and homemade white sauce, topped with cheese and baked until golden. Adaptation of Cocina al minuto (1956).

CiberCubaNovember 7, 2026

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Preparation20 min
Cooking35 min
Total time1 h
Servings4 servings
DifficultyEasy

This recipe is based on Tuna with Mushrooms, one of the preparations collected by Nitza Villapol and Martha Martínez in Cocina al minuto (1956). It is a pantry dish: canned fish, a creamy sauce, and a touch of oven to brown the top, ideal for solving a lunch or a meal without complicating things.

Our version is our own update. Instead of canned mushroom soup, we use fresh mushrooms well sautéed and a homemade white sauce, and we fix the weight of the tuna already drained so that the result comes out even. The hard-boiled egg adds body and that homey flavor that combines wonderfully with the fish.

It is not a hash nor a pasta with tuna: the tuna goes in large flakes, bathed in sauce and browned just enough to reach hot in the center without drying out.

Method

Preparation

If the eggs are not cooked, place them in a pot covered with cold water. When it comes to a boil, count 10 minutes, transfer them to cold water for 5 minutes, peel them and cut them into quarters or large chunks.
Preheat the oven to 200 °C (400 °F) and grease a shallow dish of about 22-24 cm (approx. 1.5 liters) with a little butter, or four individual ramekins of 375-400 ml.
Drain the tuna very well and separate it into large flakes with a fork, without crumbling it completely. Slice the mushrooms and finely chop the onion.

Mushrooms and sauce

Heat the oil in a wide skillet over medium heat and sauté the onion for 3 minutes, until translucent. Add the mushrooms, increase to medium-high heat and sauté them for 8-10 minutes, stirring occasionally, until they release their water, this evaporates completely and they begin to brown. Set aside.
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In a small pot, melt the butter over medium-low heat, add the flour and stir for 1-2 minutes without letting it color. Incorporate the milk little by little, beating with a whisk so that no lumps form, and let it simmer gently for 5-6 minutes, until the sauce thickens and coats the back of a spoon. Season with the salt, pepper, parsley and lemon zest if using.
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Remove the sauce from the heat and incorporate the sautéed mushrooms with the onion. Mix well.

Assembly and gratinating

Distribute the tuna flakes on the bottom of the dish and place the hard-boiled egg pieces on top. Cover everything with the mushroom sauce, spreading it evenly to the edges.
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Sprinkle the grated cheese over the entire surface.
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Bake in the center for 12-15 minutes (10-12 in ramekins), only until the sauce bubbles at the edges and the center is well hot. If more color is needed, pass 2-3 minutes under the broiler watching that it does not burn. It should remain with the surface golden and with toasted spots, without the tuna drying out.
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Let rest for 5 minutes outside the oven so that the sauce settles. Sprinkle a little chopped parsley and serve hot.

Tips and variations

Documentary source: recipe adapted from Tuna with Mushrooms, from Cocina al minuto (1956), by Nitza Villapol and Martha Martínez. The changes in this version (homemade sauce, fresh mushrooms, drained weights, times and temperatures) are ours.

Substitutions: canned tuna can replace the tuna using the same weight already drained (375 g); the texture will be somewhat more fibrous depending on the brand. If the canned fish comes in oil, drain it very well so that the sauce does not become greasy; if it comes in brine, squeeze it gently to remove the liquid. As a melting cheese, one that melts easily works well, such as gouda or mild yellow cheese; it will change the flavor and browning somewhat, so watch it during gratinating.

Sauce consistency: it should remain like a light cream that coats the back of a spoon. If it thickens too much before assembling, add one or two tablespoons of hot milk.

Salt: the canned tuna and the cheese are already salty. Taste the sauce before adding more than the indicated amount.

Storage: keep leftovers covered in the refrigerator and consume within 1 day. Reheat in the oven at 180 °C (350 °F), covered with aluminum foil, for about 10-12 minutes. Freezing is not recommended: the egg white becomes rubbery and the sauce may curdle.