Fill the kettle and boil it. Peel the onion and halve it. Slice each half into about 6 wedges. Peel and grate or crush the garlic. Rinse and halve the cherry tomatoes.
Separate the leaves from half a green cabbage and give them a wash. Slice the thick cores out of the middle of the leaves. Slice them into thin strips around 2 cm wide.
Fill a pan with hot water from the kettle. Bring to the boil. Add the spaghetti. Simmer for 8 mins till the spaghetti is cooked but not too soft. It should still have a little chew to it.
While the spaghetti cooks, heat a glug of olive oil in a deep frying pan or wok. Add the onion. Fry for 5 mins till they are starting to soften. Add the tomatoes. Fry for another 2-3 mins till soft.
Add the garlic and cabbage to the pan. Stir well. Season with salt and pepper. Add 3 tbsp water. Cook gently for 3-4 mins till the cabbage is tender.
Heat a griddle pan over a medium heat. Brush the steaks on both sides with a little olive oil. Season with salt and pepper. Add to the hot griddle pan. Cook for 2 mins on each side till charred but still pink inside (or add on an extra 1-2 mins for well done). Pop on a plate or board to rest for a few mins.
Drain the spaghetti. Divide between two warm plates. Top with the cabbage. Slice the steaks and arrange them on top of the veg.
Use a peeler to shave slivers off the Parmesan. Scatter over the beef. Serve straight away with extra Parmesan on the side.