Seared tuna steak with red onion and tomato compote

For the compote:

1 tomato, sliced, marinaded in balsamic vinegar and cayenne pepper
1 large red onion, finely sliced
3 cornichons, chopped
1 tbs black olives, chopped
2 tsp capers, chopped
1 garlic clove, bruised

1 tuna steak
1 tsp whole black peppercorns
half tsp fennel seeds
half tsp mustard seeds
sea salt
1 tbs groundnut oil

10g unsalted butter
Olive oil
chives, chopped

rocket, watercress, baby spinach or similar

This is one of those whatever's-in-the-fridge ones.

Melt the butter and a splash of olive in a large pan with the garlic clove. Cook on a medium heat until the garlic starts to colour. Add the sliced onion and sweat down. Add a splash of water, stir well, scraping up any caramelisation off the pan and into the liquid. Cover and simmer for a few minutes on a low heat, until most of the liquid has evaporated. Discard the garlic and add the tomatoes. Stir and cover again for a few minutes. Uncover and simmer gently on a very low heat. Toward the end of the cooking, add the olives, capers and cornichons.

Get a cast iron griddle pan really hot. Use a pestle to crush the spices in a mortar, and add to the groundnut oil. Coat the tuna steak in the spiced oil, and lay it in the hot pan. Cook until just done (rare is the only way), turning once.

Serve with the salad and a couple of spoons of the compote. Sprinkle the chopped chives over the top to finish.

(Quantities as for one portion, exactly how I made it!)