Recipe by Doug DiPasquale, Holistic Nutritionist
Preheat oven to 400 degrees.
Using a mandolin with the julienne (matchstick size) blade, slice sweet potato into small threads (if you don’t have a mandolin, many food processors have julienne sized blades that will suffice. As a last resort potatoes can be grated with a cheese grater, although the texture of the final product will suffer). Set aside.
Repeat process with yellow potatoes. Put yellow potatoes into a clean dish towel and wind them up over the sink, increasing the pressure as you wind and squeezing out all of the excess liquid (the drier the better). Unwind towel and add yellow potato to sweet potato. Toss in thyme, rosemary, salt and pepper and mix well.
Heat a cast iron pan on medium high heat on the stovetop. When hot, add olive oil to the pan. Put potato mixture into the hot pan, pressing it lightly to get an even thickness throughout (it should be about a 1/2″ thick).
Taking about half the butter, spoon off small knobs of butter and distribute them around the rösti, allowing it to melt underneath the potatoes. Allow to sit in the pan undisturbed for a few minutes, letting the rösti brown.
After a few minutes you need to flip the rösti. Give the pan a good shake to make sure the rösti isn’t sticking to the pan. Using a large spatula in one quick motion, flip the rösti over (this can actually be accomplished easily without a spatula by flip-tossing the rösti in the air, but requires confidence and a little practice).
Spoon out remaining butter in knobs, placing them around the rösti allowing it to melt on the underside.
Place pan in oven. This should cook in the oven for 10 minutes or so, but make sure you check it’s doneness before removing it.
Rösti can be sliced like a pie and served as a side dish for brunch, lunch or dinner. Serve with sour cream and apple sauce.