Finely dice the onion and sauté in a tablespoon of the oil over medium heat. Stir frequently for 6 minutes, allowing the onion to sweat slowly. Have on hand a cup of hot water to add as needed to prevent browning.
Add the rest of the oil and cook until the onion is translucent and tender, for about another 2 minutes.
Add the tomato and mix, allowing for the sauce to cook down for approximately 6 minutes.
Add the garlic and sauté, adding splashes of water as needed. Cook until fragrant, about 1 minute.
Add the rest of the water and bring to a boil.
Pour in the shiro powder (ground chickpeas) and stir frequently to ensure the mixture is not lumpy. Cook on high heat for another 4 minutes.
Reduce the heat slightly to a simmer, and allow to thicken. Add water as needed until you have the desired texture and thickness.
Stir in the berbere, add sea salt to taste, and garnish with Jalapeno (optional).