Blanch the tofu in boiling water for 2 minutes, then drain and pat dry. Slice the tofu in 1-inch slices, weight it down and let drain for 2 hours. In a small bowl mix together the miso and olive oil. Spread the mixture on each tofu slice, covering all the surfaces. Set the slices on a large plate, cover with waxed paper and let sit at room temperature for at least 8 hours or overnight. Scrape off and discard the miso. Crumble and use the "cheese" as you would regular ricotta. Store, covered and refrigerated, for up to one week.