5large steaks or fillets of mackerel or any fish of your choice
1teaspooncayenne pepper or chili powder
peel of 1/2 lemon
a handful of fresh cilantro
Prepare the marinade with cayenne pepper, oil and 1 teaspoon salt (reserve the other 1/2 teaspoon for mustard paste). Marinate the fish steaks for 10 minutes minimum.
Preheat oven to 100 degrees C (about 210 degrees F).
For the mustard glaze, place the rest of the ingredients except cilantro in a small blender jar and blend until smooth. (see notes)
Brush fish steaks with the mustard glaze. Sprinkle cilantro on top.
Place on a sheet pan and bake for 20 to 25 minutes until the fish flakes apart easily.
Cooking time depends on how thick the steak or fillet is. So when you're cooking this for the first time, check if the center flakes through easily, though you might hate to poke through the juicy-looking fish. If not done, bake for 5 more minutes. With practice, you can master the timing.
Cilantro can be sprinkled on the fish after cooking, but you may miss out on the cooked-mustard-cilantro-flavor so good that it can be addictive.
Since the amount of mustard paste is quite small, you will need a small blender jar to get a smooth paste. Or you can make twice or thrice the amount and freeze the leftover. That gives you an excuse to eat more of this delicious lemon-mustard glazed fish.