Start by warming the broth in a saucepan over medium heat.
Heat the 2 Tbsp butter in a pan over medium heat. Add the sliced mushrooms and place a heavy skillet on top to increase the pressure. Caste iron works great for this. This will save time and improve the flavor and consistency of the mushroom. Check occasionally. It will be slightly brown when done and soft. Remove from the pan when done and set aside.
Heat a medium-sized pot on medium heat. Add 2 Tbsp butter and the onions and cook for about a minute. Add the rice and cook for several minutes until translucent.
Pour in the wine and stir constantly until the wine is fully absorbed. Add 1/2 cup broth to the rice. Stir until the wine is fully absorbed. Continue adding broth 1/2 cup at a time, stirring continuously until the rice is done and the liquid is absorbed.
Turn off the heat and add the mushrooms, asiago cheese, salt, and pepper.
Garnish with yellow wood sorrel.