Microwave sage in a single layer on a plate until crisp, about 2 1/2 minutes.
Meanwhile, heat vegetable oil in a large pot over medium-high heat. Add 3 popcorn kernels, and cover. Once kernels pop, add remaining kernels. Shake pot over heat, covered, until all kernels have popped, about 10 minutes.
Transfer popcorn to a bowl, drizzle with olive oil, and toss to coat. Crumble sage over top. Season with salt, and toss to combine.