In a large pot, heat the olive oil over medium heat. Add the chopped onion and minced garlic, and sauté until the onion becomes translucent.
Add the diced tomatoes, bell pepper, and tomato paste to the pot. Stir well to combine.
Cook the mixture for about 5 minutes until the tomatoes start to soften.
Add the sliced okra to the pot and stir gently to coat the okra with the tomato mixture.
Season the mixture with ground cumin, ground coriander, paprika, chili powder (if using), salt, and pepper. Stir well to distribute the spices.
Cover the pot and let the stew simmer on low heat for about 30-40 minutes, or until the okra is tender and cooked through.
Stir the stew occasionally to prevent sticking and ensure even cooking.
Adjust the seasoning if needed and cook for a few more minutes.
Remove the pot from heat and garnish the Bamya with fresh cilantro or parsley.
Serve the vegan Egyptian Bamya hot with cooked rice or bread on the side.