Step 1: Preheat the oven

Preheat your oven to 180°C (350°F). Grease a baking dish with olive oil or cooking spray.

Step 2: Cook the sausages and vegetables

Heat olive oil in a frying pan over medium heat. Cook the sausages until browned and fully cooked, then slice them into pieces. In the same pan, sauté the onion and garlic until softened, about 2-3 minutes. Add the spinach and cook until wilted.

Step 3: Assemble the casserole

In a large mixing bowl, whisk together the eggs, milk, salt, and black pepper. Stir in the bread cubes, cooked sausages, sautéed vegetables, and half of the grated cheese. Mix until well combined.

Step 4: Layer in the baking dish

Pour the mixture into the greased baking dish, spreading it out evenly. Top with cherry tomatoes and the remaining cheese.

Step 5: Bake

Bake in the preheated oven for 30-35 minutes, or until the casserole is set, puffed, and golden on top. A knife inserted into the center should come out clean.

Step 6: Garnish and serve

Remove from the oven and let the casserole rest for 5 minutes. Garnish with fresh parsley or chives before serving.