Boil pasta according to package, in the last minute add the peas. Drain and rinse in cold water to stop cooking.
Meanwhile, melt butter over medium heat, add shallots and heat until translucent.
Add mushroom and cook until browned.
Add flour and cook until combined.
Add chicken stock and allow to thicken.
Continue to add stock until sauce thickly covers spoon
Add ½ cream, and ½ parm. Whisk until smooth.
Add more stock to thin down sauce, and add rest of parm.
Put pasta back in boiling pot, add drained sun dried tomatoes, chicken, pasta and peas. Add sauce on top and gently toss.