60 gmbutter, coarsely chopped6eggs, at room temperatureTo serve:thickly sliced leg ham and wilted spinachGreen onion brioche7 gm(1 sachet) dry yeast70 mllukewarm milkPinchof caster sugar500 gm(3 1/3 cups) plain flour2green onions, thinly sliced6eggs, lightly beaten, at room temperature350 gmbutter, softened1egg, lightly beaten with 1 tbsp milk, for egg washHollandaise200 gmbutter, coarsely chopped2 tbspwhite wine vinegar3egg yolks1lemon, juice only
For green onion brioche, combine yeast, milk and sugar in a small bowl, whisk to dissolve yeast and stand until foamy (2-3 minutes). Meanwhile, combine flour, green onion and 1 tsp sea salt in the bowl of an electric mixer fitted with a dough hook and mix to combine. With mixer on low speed, add yeast mixture, then eggs and beat to just combine. Add butter a little at a time, beating well after each addition. Beat until smooth (4-5 minutes), transfer to a buttered bowl, turn to coat and cover with plastic wrap. Stand in a warm place until double in size (1½-2 hours). Preheat oven to 180C. Knock back dough with fingertips and place in a buttered and floured 10cm x 10cm x 24cm loaf tin, smoothing top. Brush top with egg wash, cover with plastic wrap and stand in a warm place until double in size (25-30 minutes). Bake until light golden (15-20 minutes), cover with foil and bake until loaf sounds hollow when tapped (15-20 minutes). Turn onto a cooling rack and cool.
For hollandaise, melt butter over low heat and cool slightly. Whisk vinegar, egg yolks and 2 tbsp water in a heatproof bowl over a saucepan of simmering water until thick and foamy (2-3 minutes), then whisk in melted butter a little at a time, whisking well to emulsify before adding more. Remove from heat, whisk in lemon juice, season to taste and set aside in a warm place.
Preheat oven to 200C. Cut 6 thick slices from brioche and use an 8cm-diameter cutter to cut a hole in the centre of each slice (discard cut pieces). Heat a third of the butter in a large ovenproof frying pan over medium heat until foaming. Place 2 brioche slices in pan and cook until golden (1 minute). Turn over, crack an egg into each hole, season to taste and bake in oven until egg just sets (3-4 minutes). Keep warm and repeat with remaining butter, brioche and eggs. Transfer to serving plates and serve immediately with ham, wilted spinach and hollandaise.