To make the beans, preheat the oven to 180C/160 Fan/Gas 4.
Put the beans, garlic, sage and tomato into a roasting tin and coat in olive oil. Pour in enough water to cover the beans and then make a tight lid with tin foil. Bake for 40 minutes.
Remove the foil and put the garlic, sage and tomato into a blender. Blend to make a smooth paste, and stir into the beans. Season with salt and pepper and set aside.
Put the tomatoes and thyme into a roasting tin and coat in olive oil. Season with salt and pepper and roast for 20 minutes, until slightly dried.
To make the beef, heat a griddle pan or barbecue until smoking. Rub the steak with the oil and season both sides with salt and freshly ground black pepper. Add the steak to the hot griddle and grill for 2 minutes on each side. Leave to rest on a warm plate.
To make the salsa verde, put the anchovies, capers and garlic into a pestle and mortar and pound to a paste. Add the herbs, rocket olive oil and Dijon mustard. Season with salt and pepper.
To serve, spoon the beans onto a large serving plate. Slice the beef into thin strips and lie on top of the beans. Drizzle over the tomatoes and salsa verde. Toss the dandelion leaves with balsamic and scatter on top.