Turning on the oven to roast potatoes during the summer seems silly. But summer foods, including pesto, caponata, and fresh tomato sauce, pair so well with potato gnocchi that it's worth the hour or so of extra kitchen heat. And if you break the process down into two steps: making the gnocchi and then freezing them for later, you're guaranteed a quick summer dinner. Once frozen, all you need is to boil the gnocchi, top with sauce, and enjoy.
Without wheat flour to bring stretchy gluten to hold the gnocchi together, starchy potatoes provide the structure that we need. So be sure to select russetts or Idaho potatoes for the recipe.
To further ensure the gluten-free gnocchi hold together during cooking, you need to bake, not boil, the potatoes. Baked potatoes not only reward you with a stronger potato flavor, they don't absorb water during the cooking process. During testing, batch after batch of gnocchi made with baked potatoes used approximately one to one and a half cups of gluten-free flour. The same recipe made with boiled potatoes sometimes required up to two and half cups of flour, leaving the gnocchi heavy and unpleasantly gummy.
Thanks to the starchy, roasted potatoes, we don't need to use a complex gluten-free flour blend or xanthan gum for this recipe. A simple mix of white rice flour and sweet rice flour does the trick. And the sweet rice flour is important. Made with only white rice flour, the gnocchi were too soft. A half cup of sweet rice flour, which is ground from glutinous, short-grain rice, added a nice bite without making the gnocchi gritty.
Once you've roasted the potatoes and whisked together your flour, it's time to shape them.