In a medium saucepan, bring the chicken stock to a simmer. Keep warm.

In medium saucepan, melt 1 tablespoon butter in oil over medium-low heat. When it foams, add onion and garlic; cook until softened. Pour in rice and stir to coat. Cook, stirring slowly, until rice is lightly toasted, about 3 minutes.

Pour in 1 cup wine and reduce over medium-high heat until almost gone. Add second cup and reduce once more. When pan liquid is syrupy, begin ladling in hot broth, ½ cup at a time. Stir rice and adjust heat so that it is just bubbling on the edges. Continue stirring and adding broth as needed. Rice is done when it is tender but still firm to the bite in center. If you run out of broth before rice is cooked, add hot water. Mixture should be creamy and loose, not soupy. Taste and adjust seasoning.

Meanwhile, in a large skillet, melt the butter. Add the mushrooms and shallot, season with salt and pepper, and cook over moderately high heat, stirring occasionally, until softened and browned, about 10 minutes.

Scrape the mushrooms into the risotto and stir in ½ cup cheese and tablespoon of butter. Fold in herbs. Serve immediately, passing remaining cheese at the table.