Heat olive oil in large heavy saucepan. Add shallots and garlic; cook and stir 4-5 minutes until tender. Add tarragon and mushrooms; cook, stirring frequently, for 5-6 minutes until mushrooms give up their liquid.
Add rice and toast, stirring frequently, for 5-6 minutes. While rice is toasting, place broth in small saucepan and heat over low heat.
Add wine to rice mixture in pan; cook, stirring constantly, until rice absorbs wine.
Then start adding the broth, about 1/2 cup at a time, until the rice is al dente. This should take 20-25 minutes. Add more broth, or water (that works just fine) if you like a soupier risotto.
Add parsley, salt, pepper, cream, cheese, and butter and stir. Remove from heat, cover, and let stand 5 minutes, then serve.