1 Cutting board, 1 Small knife, 1 Baking sheet, 1 Bowl, 1 Kitchen towel, 1 Large knife, 1 Paper towel, 1 Tablespoon, 1 Saute pan, 1 Slotted spatula, 1 baking dish
1 Trim wax peppers, cut in half lengthwise, remove seeds and rinse. With the cut side down, place on a baking sheet and broil under the oven broiler until the skin is black and blistered.
2 Meanwhile, peel onion and chop finely. Remove garlic from the skins.
3 Rinse tomatoes and cut out the stem ends.
4 Pour boiling water over tomatoes in a bowl and let soak for 2 minutes. Drain and rinse in cold water. Peel tomatoes, cut in half, remove seeds and dice finely.
5 Take wax pepper halves from the oven. Put the peppers on a moistened cloth and allow to cool slightly. Remove the skin and cut the peppers into strips crosswise.
6 Remove head and tail from mackerel (or have this done by the fishmonger). Rinse the fish, pat dry with paper towels and cut into inch-thick slices. Season with salt and pepper.
7 Heat the olive oil in a large sauté pan. Fry mackerel pieces over medium heat, turning to brown evenly, about 5 minutes.
8 Remove fish and spread in a large oven-proof baking dish. Add the onion, garlic and peppers to the pan and sauté for about 2 minutes in the remaining olive oil.
9 Add diced tomatoes and salt and pepper to taste and cook everything for another 5 minutes over medium heat.
10 Spread the vegetables over the mackerel pieces and cook in a preheated oven at 180°C (fan 160°C, gas mark 2-3) (approximately 350°F/convection 325°F), about 15 minutes.