Set up your pressure cooker and turn to saute. Add in the oil and then the carrots, celery and shallots and saute for 2 minutes. Next add in the garlic and cook for 1 minutes. Now add in the tomato paste and stir and cook for another minute.
Next, add in the squash and all the spices. Mix well and add the stock, chicken and marsala and change pressure cooker to slow cooking. Cook for 45 minutes and release steam when complete. Serve on top of white rice.