Toast the hazelnuts in an ungreased skillet over medium-high hear,
stirring frequently, until the nuts are darkened in spots, 5 to
7 minutes. Cool enough to handle, coarsely chop, and set aside.
Heat the oil in a large sauté pan or wok. Stir in the onion and
garlic and sauté over medium heat until translucent, about 5 minutes.
Add the greens in batches, stirring them down after each addition,
until all are in the pan. Stir-fry until tender, 8 to 12 minutes,
depending on the age of the greens.
Stir in the hazelnuts and salt and pepper to taste. Toss gently
and serve right away.
~ Add a small splash of hazelnut oil when stirring in the hazelnuts
at the end.
~Add a dash of orange or lemon juice when stirring in the hazelnuts.
~Garnish with orange or lemon zest.