Once you know what to make, the cooking part is
fairly easy and fun... so sit down on a
slow Sunday with a cup of tea, and write out a
week of menus.
I also walk at least a couple of times per
week, either going for a family hike (typically
fairly rigorous) or walking the mile uphill pushing my youngest in the stroller to pick my oldest up at school (and then the much
slower walk back downhill returning home), which we try to do twice per
week.