Ingredients: 

• 1 box of Roma Lasagna
• 2 tablespoons of skimmed milk
• 4 tablespoons of flour
• 1⁄4 stick of butter
• 1 zucchini, julienned
• 1 bell pepper, roasted and julienned
• 1 cup of chopped mushrooms
• 1⁄2 cup of tomato sauce
• 2 onions, chopped
• 2 cloves of garlic, crushed
• 3 cans of tuna in oil
• Drained Tuna oil
• 400 g of grated mozzarella
• Salt and pepper to taste

Preparation:   

1. Cook the pasta following the instructions on the package and preheat the oven to 180° C.
2. Pour the oil drained from the tuna cans into a pan and fry the onions and garlic for 1 minute and then add the zucchini, bell peppers, mushrooms, tomato sauce, and tuna previously shredded. Add water to make the sauce lighter and cook for 3 more minutes.
3. In another pan, melt the butter, add the flour, and stir. Then add the milk and stir constantly to prevent lumps from forming. Season with salt and pepper, and once it has thickened, remove from heat.
4. Butter the bottom of a casserole and start assembling the lasagna: one layer of lasagna sheets, one layer of tuna mixture, one layer of white sauce, and one layer of mozzarella. Repeat the layers until the ingredients run out.
5. Bake the lasagna in the oven following the recommendations on the packaging, until the cheese has melted and served.