This really is an easy recipe, as in every step of it is easy. The puff pastry comes out of a box, and all you need to do is chop the rhubarb, mix it with sugar and a few other ingredients, dump all of it into the pastry, fold in the edges, and bake. It will look great in the end, and a galette is meant to be rustic anyway, so don't sweat the process. I was lucky to get some bright red rhubarb stalks, but if you can only find ones that are mildly colored or greenish, don't fret. Your tart will still taste amazing. Cut the rhubarb in thin, 1/4th-inch slices to ensure it cooks thoroughly. Most rhubarb recipes pair this veggie with cinnamon or nutmeg. But I love mixing in some cardamom, especially in this galette. It adds intoxicating flavor to an already delicious dish, just that extra bit of je ne sais quoi. Most pie recipes need to be cooled thoroughly before you can eat them, and it's the same for this galette. Cooling the galette gives the juices that have oozed out during cooking to gel and firm up so you can easily slice the pie. So as badly as you may want to eat your galette the minute it comes out of the oven, be patient.