To build your off-the-cuff kitchen repertoire, take cues from the flavor combinations in The Creative Cook Menu .
Heat 1 tablespoon olive oil in a 10" nonstick skillet over medium heat. Add leeks and bell pepper; season to taste with salt and pepper. Cook, stirring occasionally, until softened and just golden, 6 to 8 minutes. Transfer to a large bowl and set aside; rinse and dry skillet.
Meanwhile, grate potatoes on large holes of a box grater. Working quickly (they discolor after grating) with a small handful at a time, firmly squeeze potatoes to remove as much liquid as possible; discard liquid and transfer potatoes to bowl with leek mixture.
Add thyme, 1 1/2 teaspoon salt, and 1/2 tsp. pepper to mixture; toss well.
Heat 1/2 tablespoon butter and 1/2 tablespoon olive oil in skillet over medium heat. Add potato mixture; press down firmly with a rubber spatula to form a potato cake. Tidy the edges, then cook, gently shaking skillet from time to time to prevent sticking, until cake is a deep golden brown, 8 to 10 minutes.
Loosen edges, then gently slide hash browns onto a large plate. While heating remaining butter and olive oil in skillet, place a second plate on top of hash browns and flip (so cooked side will face up). Glide inverted cake back into the warmed skillet and cook until deep golden brown on second side, 8 to 10 minutes. Slide hash browns onto a platter. Cool for 5 minutes, then cut into wedges and serve.
Extra idea: For another brilliant union, combine the same flavors to create a warm potato salad.