Ingredients :

• Canned tuna in water — Not in oil — in water. Oil weights down the mixture and creates a greasy result that doesn’t set well. Drain it thoroughly: press the lid down hard and let it drain over the sink for a good thirty seconds. The final texture depends directly on this.
• Heavy cream — Low-fat cream (15%) results in more watery flans that don’t hold their shape as well. Use heavy cream (30%); it provides that melt-in-the-mouth quality that makes all the difference. If you only have light cream, compensate with a spoonful of Greek yogurt or fromage blanc.
• Grated cheese — Standard supermarket grated Emmental or Gruyère works perfectly. This isn’t the time to break out an 18-month Comté — its flavor would overpower the tuna. For more stretch, grated mozzarella is a great option.
• Flour (optional) — One tablespoon is enough. If you like your flans a bit wobbly in the center, skip this ingredient. With flour, they are firmer and easier to unmold. Without it, they are creamier and more delicate. Both versions are worth trying.