Bring a large pan of water to the boil. Add the beans and simmer for 1 min, add the broccoli and then cook for 3 mins more until tender. Drain.
Meanwhile, heat a large frying pan and gently toast the hazelnuts until golden brown. Add the butter, let it melt and foam for just a few mins, but don’t let it burn, then season well. Tip the drained vegetables into the frying pan and toss in the butter until everything is coated.