First thing, chop and mince all the vegetables so they're ready to go when you need them.
Make the sauce: Heat the olive oil in a medium saucepan over medium heat. Add the ginger, garlic and chile pepper and cook about 1 minute. stirring consistently while ginger and garlic lightly brown. Add the garam masala and paprika and cook 30 seconds. Add the tomato sauce and 1 cup water, stir and bring to a boil. Reduce the heat to low. Simmer, uncovered 15 minutes.
Prepare the sloppy joes: Heat 2 tablespoons olive oil in a large skillet over medium heat. Add the raisins and pistachios and cook, stirring occasionally, until the raisins swell up and the pistachios toast slightly, about 1 minute. Remove from the skillet and set aside.
Return the skillet to medium heat and add the remaining 2 tablespoons olive oil. Add the cumin seeds and let sizzle about 10 seconds, then add the onion and bell pepper and cook until softened and starting to brown, about 5 minutes. Add the chile pepper and cook 2 more minutes, adding the 1/2 teaspoon salt. Add the meat, breaking up the big lumps, and cook about 5 minutes, stirring occasionally.
Add the prepared sauce to the meat and onion mixture in the skillet. Stir and bring to a boil, then reduce the heat to low. Cook until the sauce reduces and thickens, about 12-15 minutes.
Remove the whole chile pepper. Stir in the raisins and pistachios. Taste for seasoning. Stir in the cilantro right before serving.
Toast buns or rye bread and fill with the sloppy joe mixture.