Heat oven to 375°F and arrange a rack in the middle.
Place sweet potato on a foil-lined, oven-safe frying pan and poke it several times all over with a fork. Roast in the oven until very soft, about an hour. Let cool. Leave oven on.
Meanwhile, heat olive oil in a large frying pan over medium-high heat. Add onion, both bell peppers, and jalapeño and cook, stirring occasionally, until tender. Add garlic and cook a minute more.
Add ground beef and brown, breaking up with the back of a wooden spoon. Add paprika, 2 teaspoons of salt, cumin, coriander, and oregano. Let spices toast as the meat finishes browning. Add tomatoes and cook a few minutes more, just until they start to break up. Transfer meat mixture to a 14-inch cast iron skillet or a 9 x 13-inch baking pan.
Once sweet potato is cool, remove the skin and place in a medium bowl. Mash the sweet potato then stir in the soy milk, vinegar, oil, and egg and beat until smooth.
In a separate large bowl whisk together the flour, cornmeal, sugar, baking powder, baking soda, and remaining 1/2 teaspoon of salt. Add the wet mixture to the dry and stir until well combined.
Spread the batter over the meat mixture and bake until crust is cooked through and golden, about 20-25 minutes.