Heat the vegetable oil in a large pot over medium heat.
Add the chopped onions and cook until soft and translucent, about 5 minutes.
Stir in the minced garlic and ginger, and cook for another 2 minutes until fragrant.
Stir in the tomato paste, ground cumin, ground coriander, ground turmeric, paprika, and berbere spice mix (if using). Cook for 1-2 minutes.
Add the chicken pieces to the pot and cook until browned on all sides.
Add the diced tomatoes and water or chicken broth, stirring to combine. Bring to a boil.
Reduce heat to low and simmer for 30-40 minutes, or until the chicken is cooked through and tender.
Season with salt and black pepper to taste. Garnish with fresh cilantro before serving. Serve Tsebhi hot with injera, rice, or bread.
Enjoy your meal!