In a large deep skillet (use a 3.5-quart or larger pot), heat the olive oil over medium heat. Saute the onion and bell pepper until they soften, about 5 minutes.
Add in the garlic and ginger and saute for 1 minute more, just until they are fragrant. Add in the curry powder, cumin, and turmeric and stir until the vegetables are coated with the spices.
Pour in the crushed tomatoes and coconut milk, and season with 1 teaspoon of salt. Bring the liquid to a boil.
While the curry sauce is heating up, break up the rinsed jackfruit with your fingers, creating a texture similar to shredded chicken. Rinse the jackfruit again, after it has been shredded, to remove any extra brine, then drain well. Add the drained jackfruit to the sauce.
Once the sauce is boiling, lower the heat to a simmer to let the flavors meld, at least 10 minutes, but you can let it simmer longer if you like.
When everything is heated through, taste the sauce and adjust any seasoning to your taste. You can add a splash of maple syrup if you prefer a sweeter curry sauce, or add extra curry powder or a pinch of cayenne if you like it spicier. Serve warm over cooked rice, and garnish with fresh cilantro.
If you can't find fire-roasted tomatoes, you can use regular crushed tomatoes instead. The fire-roasted variety are naturally more sweet and flavorful, so you may want to adjust the final seasoning to your taste when making substitutions.
If you don't have coconut milk on hand, cashew cream can be used as a substitute. I use 1/2 cup of cashew cream + 1 cup of water to replace 1 can of full-fat coconut milk.