Cook the farro in 3 cups of the broth, for about 10-15 minutes, or until most of the liquid is absorbed, and farro is slightly tender but still has some firmness.
While farro is cooking, soak the dried porcini mushrooms in 1 cup hot water for about 15 minutes. Remove the mushrooms to a strainer (reserving the liquid), and rinse well, to remove any grit. Strain the mushroom liquid through a coffee filter to make sure it's clear of any grit. Chop both the porcini, and the cremini mushrooms.
Heat the olive oil in a large sauté pan over medium high heat, and add shallots. Cook 3-5 minutes, or until translucent. Add the mushrooms, and then the wine, and sauté for another 3 minutes or so.
Add the cooked farro to the shallots and mushrooms, and immediately add the reserved mushroom liquid. Stir gently, and reduce the heat to low.
As the liquid is absorbed, add additional broth, about ½ cup (or a ladle full) at a time, and stir occasionally as it simmers. Add additional broth as needed, up to 2 cups, until farro is completely tender and creamy.
When farro is just about finished, add asparagus and simmer for a final 3-5 minutes, or until asparagus is tender.
Stir in ¼ cup grated cheese.
Serve, passing additional cheese if desired.