THAI-STYLE FRIED GREENS WITH CRISPY SHALLOTS

200g shallots, finely sliced (use a mandoline if possible) • 300ml vegetable oil • 1 tsp caster sugar • 1 tbsp soy sauce • 2 tbsp oyster sauce • 200g Tenderstem broccoli, trimmed • 200g Swiss chard, trimmed • 4 garlic cloves, finely chopped • 115g pack baby leaf spinach • 1 red chilli, finely sliced