In a Dutch oven, warm the palm oil over medium heat, and add the onions, garlic, ginger, chile and a couple pinches of salt.
Cook, stirring frequently, until the onions are golden brown and sweet, about 15 minutes.
Stir in the tomato paste, and cook for 3 minutes.
Add the tomatoes and a few generous pinches of salt. Bring to a boil, lower heat to a simmer and partly cover the pan.
Simmer, stirring occasionally, until the sauce has cooked to a rich tomato-soup consistency, about 25 minutes.
Meanwhile, pulse the egusi or pumpkin seeds in a food processor or blender to a fine powder, until it just starts to get clumpy. (Do not overprocess into a butter.) Remove to a bowl.
When the tomatoes have reduced, add the shrimp powder (or smoked paprika and fish sauce to taste), and simmer 2 minutes.
Stir in water, a tablespoon at a time, to the bowl of egusi powder until it is a loose paste. Add the egusi paste on top of the tomato sauce, and spread it out.Cover the pan, and cook 5 minutes.
Stir the sauce all together; it will look like a thick porridge.Add a few splashes of water, and increase heat to a boil.
Stir in the spinach, until wilted and tender.
Taste, season with salt (or more fish sauce, if using) and serve with boiled sweet plantains.