- Preheat your oven to 200°C (180°C fan/gas mark 6). 
- Lightly season the chicken breasts with salt and pepper, and wrap them in foil to keep them moist. Bake in the oven for 20-25 minutes, or until the chicken is cooked through. Once cooked, allow the chicken to cool slightly, then dice or shred. 
- Boil the pasta in salted water according to the packet instructions until al dente. Drain and rinse under cold water to cool quickly. Set to one side. 
- In a small bowl, whisk together the fat-free natural yoghurt, light mayonnaise, Dijon mustard, and lemon juice. Season with salt and pepper to taste. Set to one side. 
- Once the chicken and pasta are all cooled. In a large bowl, combine the diced or shredded chicken, defrosted peas, and sliced spring onions. 
- Add the cooled pasta to the bowl with the chicken, peas, and spring onions. Pour over the dressing and mix until everything is evenly coated. 
- Cover and refrigerate for at least 30 minutes before serving to allow the flavours to meld together.