In a small bowl, combine honey, tamarind paste, soy sauce, minced garlic, thyme, black pepper, and a pinch of salt. Mix well until smooth.

Place the filet mignon steaks in a large resealable bag or a shallow dish. Pour the marinade over the steaks, ensuring they are well coated. Seal the bag or cover the dish and refrigerate for at least 1 hour, preferably overnight for maximum flavor.

In a large skillet or Dutch oven, heat olive oil over medium heat. Add the sliced sweet onions and sauté for about 10-12 minutes until they are caramelized and golden brown. Remove the onions from the skillet and set aside.

In the same skillet, increase the heat to medium-high. Remove the steaks from the marinade (reserve the marinade for later) and sear them for 3-4 minutes on each side until they develop a nice crust. Remove the steaks and set aside.

Pour in the beef bone broth and reserved marinade into the skillet, scraping up any browned bits from the bottom. Bring to a simmer.

Return the steaks to the skillet, nestling them among the onions. Cover the skillet and reduce the heat to low. Allow the steaks to braise for 15-20 minutes for medium-rare, or longer if desired, ensuring the internal temperature reaches your preferred doneness.

Once cooked, remove the steaks from the skillet and let them rest for a few minutes. Increase the heat to medium-high and reduce the sauce for an additional 5-7 minutes until thickened.

Slice the filet mignon and arrange it on plates with the caramelized sweet onions. Drizzle the rich bone broth reduction over the top. Garnish with fresh parsley and serve immediately.