Sure, here is the recipe for Mackerel and Onion Tomato Stew in English:

## Mackerel and Onion Tomato Stew

**Ingredients:**

* 1 (190g) can of mackerel in water, drained
* 1 onion, thinly sliced
* 2 cloves garlic, minced
* 2 tablespoons olive oil
* 1 (14.5 oz) can diced tomatoes