Fill the kettle and boil it. Peel the onion. Halve it. Cut each half into about 6 wedges. Peel and crush or grate the garlic. Halve the tomatoes.
Halve the cabbage. Save one half for later (see our handy tip). Remove any tatty outer leaves. Shred it. Rinse in a colander. Drain and pat dry.
Fill a pan with hot water from the kettle. Bring to the boil. Add the spaghetti. Simmer for 8 mins till the spaghetti is soft with a little chew to it.
Heat 1 tbsp olive oil in a large frying pan or wok. Fry the onions over high heat for 3 mins till beginning to soften. Add the tomatoes and fry for 2 mins till both are soft.
Add the garlic and cabbage to the pan. Stir well. Season. Add 3 tbsp water. Cover the pan with a baking tray or lid. Let the cabbage steam for 3 mins. Drain the spaghetti.
Heat a griddle pan over medium heat. Brush the steaks on both sides with ½ tbsp olive oil. Season with a little salt and pepper. Cook the steaks in the hot griddle pan for 2 mins on each side till charred but still pink inside.
Transfer the steak to a board and rest for 1-2 mins. Divide the spaghetti between two warm plates. Top with the veg. Cut the steak into 2 cm slices. Place on top of the veg. Serve straight away.