2. For caramelized onion, place a skillet on very high heat, and drop onions in it. Let it cook for 4 minutes.
3. Add maple syrup and mix well.
4. Sprinkle salt and pepper. Cook for about 20 minutes or until caramelized, stirring occasionally.
5. For casserole, in a large mixing bowl, add caramelized onion, heavy cream, wine, and egg. Mix well.
6. Drop thyme leaves, pepper, salt, bouillon cube, and flour.
7. Throw garlic, sage and a little bit of grated cheese. Stir to combine.
8. Place a frying pan on medium high heat, and melt butter in it. Swirl and spread it all over the pan.
9. Drop chicken pieces and let them caramelize.
10. Season it with salt and pepper. Flip and cook on other side.
11. Grease a baking dish, and pour egg mixture in it.
12. Place chicken on top, and sprinkle remaining cheese on top of dish.
13. Pop it in oven and bake for 45 minutes.