Heat oil in a large pot. Add onion and cook, stirring often, until translucent. Add 1 tablespoon butter, garlic, mushrooms, and thyme. Cook until the mushrooms have softened and are golden, then season with salt and pepper. Remove mixture from the pot.
Melt remaining tablespoon butter in the pot and add the arborio rice, stirring quickly. Cook until the grains are well-coated and smell slightly toasty. Add the wine and cook until the wine has mostly absorbed.

Add about 1 cup hot broth. Stirring often, cook until the rice has mostly absorbed liquid. Add remaining broth about 1 cup at a time, continuing to allow the rice to absorb each addition of broth before adding more. Stir often and cook until the risotto is al dente and creamy, not mushy.
Add the mushroom mixture back into the rice.
Stir in Parmesan and peas then garnish with parsley. Serve warm

Step by step video https://youtu.be/p50L3hmlLMg?sub_confirmation=1