Clean and wash the cauliflower. Cut into florets. Cook in a pot of boiling salted water on medium-high heat for 10 minutes until tender.
Peel and finely chop the 3 onions. Heat 1 tablespoon oil in a large pan over medium-high heat. Add the 500 g minced meat and cook for 5 minutes, breaking it apart until crumbly and cooked through.
Add the chopped onions, 1 tablespoon Herbs Provence, and 2 tablespoons tomato paste to the pan. Sauté over medium heat for 2 minutes. Season with salt, pepper, and paprika to taste.
Stir in roughly 375 ml water. Bring to a boil over medium-high heat, then reduce to medium and simmer for 2 minutes.
Pour the minced meat sauce into an ovenproof dish. Drain the cauliflower and place it in the sauce. Spread the 100 g grated Gouda cheese evenly over the top. Distribute the 20 g butter in small flakes.
Bake in a preheated oven at 200°C (400°F) for conventional ovens, or 175°C (350°F) for convection, for 10 minutes until the cheese is melted and lightly golden.