1Season the cubed beef with salt and pepper. Heat olive oil in a Dutch oven and brown the beef in batches, then remove and set aside.
2Add the sliced cremini mushrooms to the Dutch oven and brown them for 4 to 5 minutes.
3Add the diced yellow onion and diced red bell pepper. Cook for another 4 to 5 minutes.
4Add the minced garlic and grated ginger, cooking for 1 minute.
5Stir in the tomato paste, turmeric, and smoked paprika, cooking for 1 to 2 minutes. Pour in the red wine to deglaze the pan, scraping up any browned bits, and reduce for 2 to 3 minutes.
6Return the browned beef to the pot. Add the beef stock and fresh thyme sprigs. Cover and simmer for 1.5 to 2 hours until the beef is tender.
7Remove the thyme sprigs. Add the cubed sweet potato and rinsed red lentils. Simmer uncovered for 20 to 25 minutes until tender.
8Whisk the white miso with 0.5 cup of hot broth from the pot, then stir the mixture back into the stew. Add the dark chocolate and stir until completely melted.
9Add the baby spinach and stir until wilted. Turn off the heat and add the lemon juice. Taste and season as needed.