In a large pot or Dutch oven, heat the oil over medium heat. Add the onion, garlic, and ginger. Cook until the onion is translucent. Sprinkle with the chili powder, curry powder, mustard seeds, cumin, salt, and chili flakes and continue to cook for 3-5 minutes, until the onion is coated and the spices are fragrant.

Add the jackfruit and broth to the pot and bring to a boil. Lower the heat to medium-low, cover, and cook, stirring occasionally, for about 30 minutes, until the liquid is almost all evaporated and the jackfruit begins to soften. Use 2 forks to gently pull the jackfruit apart into shreds.

Pour the crushed tomatoes into the pot with the stevia and lemon juice and stir to combine. Cover and continue to simmer until the sauce is dark, thickened, and the jackfruit is tender. Serve over hot rice. (Can be frozen and reheated later.)