Ground coffee may seem like an unusual ingredient here, but it brings out the earthy sweetness of beets.
Preheat oven to 425 degrees. Scrub beets and arrange on parchment-lined foil. Drizzle with oil and sprinkle with coffee; season with salt and pepper. Wrap tightly and place on a rimmed baking sheet. Roast until easily pierced with the tip of a knife, about 1 hour. Let cool completely; remove skins and slice beets.
In a large skillet, heat oil over medium. Add garlic; cook until fragrant, about 1 minute. Add beet greens and stems, season with salt and pepper, and cook, stirring occasionally, until wilted and tender, 2 to 4 minutes.
Spread ricotta over toasts and top with greens, then beets. Season with salt and pepper, drizzle with oil, and serve, with lemon wedges.