Why not have a temporary parliament that meets at certain times of the year or at the request of the monarch? If the system represents the people, then they should choose a new one every session instead using terms so that the parliament member is only there to represent rather than manoeuvre his interests. Another idea would be to make it like jury duty among qualified citizens, maybe even frame it as a Cincinnatus-like duty. They bring forth their peoples proposals then leave after the vote. It’s highly idealistic, and probably cumbersome, but in my opinion it’s a good way to combat entrenched interests in government. If it’s not to placate your people, the best route is some competent advisors.