The Hearty Bean and Sausage Casserole is a nourishing meal that perfectly blends the earthy flavors of mushrooms and beans with the rich taste of pork or beef sausages. Starting with a base of halved button mushrooms and sausages, baked to perfection with a drizzle of olive oil, this dish layers flavors by sautéing red onion and leek until they're tender and golden. The casserole becomes a creamy delight with the addition of a puree made from cannellini beans, water, and Dijon mustard, enriching the dish's texture and taste. A second helping of whole beans, a sprinkle of nutmeg, and baby spinach are stirred in, with the spinach wilting beautifully into the mix.
Begin by preheating the oven to 180°C/350°F/Gas 4.
Place the mushrooms and sausages in a large flameproof and heatproof casserole dish. Drizzle with 1 tablespoon of olive oil and bake in the preheated oven for approximately 30 minutes.
Meanwhile, heat the remaining olive oil in a frying pan over medium heat. Sauté the onion and leek for about 20 minutes, stirring occasionally, until they soften and develop a golden hue.
Using a stick blender or food processor, blend together water, mustard, and 1 tin of beans until you achieve a smooth purée.
Add the softened onion and leek, roasted mushrooms and sausages, the second tin of beans, bean purée, nutmeg, and spinach into the casserole dish. Place it on the hob over low heat until the spinach wilts. Season with salt and pepper to taste, and top with crème fraîche before serving.