Great dish for a summer dinner or lunch. Crispy green beans and a velvety mushroom sauce are a combination that many will love.
Peel the onion, cut into 4 pieces and thinly slice. Heat a frying pan with olive oil and fry the onion until golden brown. Transfer to a plate.
Add some more oil to the pan and add the breadcrumbs. Fry until golden brown, stirring constantly, 3-5 minutes. Remove from heat and stir in the fried onion and Parmesan, season with salt.
Cut the mushrooms into thin slices, chop the garlic. Heat the olive oil in a frying pan and sauté the mushrooms, 5 minutes. Add garlic and continue frying for 2 more minutes. Sprinkle the mushrooms with flour and mix, fry for 1 minute. Gradually add the broth and milk, stirring constantly, and bring the sauce to a boil. Simmer over low heat until the sauce thickens, 2 to 3 minutes. Add the remaining parmesan, salt and pepper, stir and remove from heat.
Preheat oven to 180°C. Cut green beans into pieces and place in a pot of boiling salted water. Simmer for 3 minutes, then drain in a colander and rinse with cold water.
Toss the green beans with the mushroom sauce and place in an oiled baking dish. Then spread onion topping. Place the mold in the oven and bake for 25 minutes. Serve hot.