Fish and chicken in olive oil: marinades and roasting

Olive oil makes a good marinade base for a simple chemical reason: most of the flavour compounds in herbs, garlic and spices dissolve in fat rather than water. Oil draws those flavours out and carries them onto the surface of the meat.

A base marinade

Three parts olive oil to one part acid — lime, lemon or vinegar — with salt, garlic and whatever herbs you have. That is all.

That is the same ratio as a salad dressing, because it works the same way. The oil carries flavour; the acid changes the surface of the meat.

How long to marinate

• Fish: 15 to 30 minutes, no more. Acid starts to "cook" fish and the texture turns chalky
• Chicken breast: 30 minutes to 2 hours
• Chicken on the bone with skin: 2 to 6 hours, or overnight in the fridge
• Vegetables: 15 to 30 minutes is plenty

The time limit on fish is the one that matters most. If you want to marinate fish for longer, leave the acid out and use olive oil, garlic and herbs alone, then add a squeeze of lime after cooking.

Grilled or baked fish

Fish needs less oil than any other protein. Brush a thin film of olive oil onto the fish and the tray, season with salt, and bake.

As soon as it comes out, pour raw olive oil and a squeeze of lime over it. This is the standard method across the Mediterranean and it works with almost any fish available here.

Roast chicken

Toss chicken pieces with olive oil, salt, garlic and black pepper, and roast at a moderately high temperature until the skin browns. Olive oil helps the skin crisp without the scorching that butter can cause.

Add vegetables to the same tray — potato, carrot, onion — tossed in the same oil. They cook in the fat running off the chicken and need no separate tray.

A note on heat

Oven roasting at a moderately high temperature sits comfortably within extra virgin's range. Grilling directly under a very hot element, or over open coals, can exceed its smoke point — if the oil starts to smoke, move the food further from the heat.