Replaced the cream with half & half, which decreased calories and didn't seem to mess with consistency of sauce. I agree with another user who said the roux wasn't really necessary; I added it, but the consistency seemed thicker than picture. I probably overdid it measuring the peas, which didn't help.
Otherwise, I thought the lemon was well balanced and overall the sauce was the best part of the dish. Would recommend either cutting the roux or increasing chicken broth and/or cream to improve consistency. Would probably make again, with some tweaks.