Peel and de-seed the butternut squash. Cut the peeled butternut squash into a large dice of about the same size. Prep your other veggies; peel the onion and cut into a large dice, peel the carrots and cut into large pieces, wash the celery and cut into large pieces, peel the garlic cloves. Place the butternut squash, carrots, onions, celery, and garlic into your pressure cooker. Add the thyme and parsley leaves. Cover with the chicken stock, and then add the salt and pepper.