Preheat oven 220℃/430℉. Line an oven tray with baking paper. Mix all Thai marinade ingredients together, or bash together in a mortar and pestle, until a chunky paste forms.
Coat chicken breasts in Thai marinade and set aside to marinate at room temperature. (If you have time, marinate for a few hours or overnight.) Toss pumpkin wedges with olive oil and sweet chilli on prepared oven tray and season with salt and pepper. Sprinkle over sesame seeds and chilli flakes, if using. Spread out in a single layer and roast for about 20 minutes or until soft and starting to caramelise. Turn pumpkin over.
Place chicken breasts on tray with pumpkin, season with salt and return the tray to the oven to roast for a further 15-20 minutes or until chicken is cooked through and pumpkin is well caramelised, Remove chicken from oven and set aside to rest for 5-10 minutes.
Scatter lighlty washed baby spinach on top of pumpkin and returm tray to the oven for a further 2-3 minutes until spinach is just wilted.
To serve, divide pumpkin and spinach between plates. Slice chicken breasts and place on top. Spoon over any resting juices from the chicken and oven tray. Squeeze over a wedge of lime just before eating.
Notes
Lim, Nadia (2015) Nadia Lim's Fresh Start Cookbook Penguin Random House