Combine the peanut butter with 1 cup [240 ml] stock and stir to make a smooth sauce.
In a large saucepan, heat the oil over medium heat and add the onion and bell pepper. Sauté until soft but not browned, about 3 minutes. Add the garlic and stir until fragrant, about 30 seconds.
Add the tomato paste, stirring to evenly coat the vegetables. Allow to cook until the mixture is brick red, 3 to 4 minutes. Add the diced tomatoes with their liquid. Stir and scrape the bottom of the pan to loosen any stuck bits. Bring the sauce to a simmer.
Stir in the peanut butter sauce and the remaining 2 cups [480 ml] stock. Add the tamarind paste, fish sauce, bay leaf, and habanero. Let the sauce simmer over low heat, covered, until slightly thickened, about 30 minutes. Stir frequently to keep from burning.
Add the sweet potato, turnips, and carrot. Season the sauce with the salt and pepper and allow to cook until the vegetables are just tender, 12 to 15 minutes. Remove the habanero, being careful to keep it whole. Discard or set aside to use as garnish. Add the okra and cook until just tender, another 3 minutes.
Sprinkle in the baobab powder and stir in the spinach. Remove from the heat. If too thick, thin with up to 1 cup [240 ml] additional stock.
Remove the bay leaf, taste for salt, and serve.