Roast the Shiro Powder: Add the chickpea flour, berbere powder, ground cardamom, cumin powder, and garlic powder to a large dry skillet.Dry-roast the mixture, stirring as needed, then set it aside. The salt can be added at this stage or adjusted later while preparing the stew. Heat the Olive Oil: Place a medium-sized pot or Dutch oven over low to medium heat and add the olive oil.
Cook the Onion: Add the diced onion and cook for about 1–2 minutes, just until the aromatics become fragrant. Do not allow the onion to brown.
Add the Garlic and Tomato Paste: Stir in the minced garlic and tomato paste. Sauté for about 30 seconds, until the garlic becomes fragrant. Add the Shiro Powder and Water: Add the prepared shiro powder to the pot along with 3 cups of water and salt. Stir the ingredients together and bring the mixture to a boil over medium heat. Simmer the Stew: Reduce the heat to low to medium and allow the Shiro Wat to simmer for approximately 20–30 minutes, depending on the consistency you prefer.
Stir Regularly: Stir the stew at approximately 5-minute intervals during simmering to help prevent it from sticking to the bottom of the pot.
Check for Doneness: Continue cooking until the mixture has thickened to your desired consistency. The oil floating to the surface is a visual sign that the Shiro Wat is finished cooking. Adjust and Serve: Taste the stew and adjust the salt as needed. Serve hot with rice or injera.