In a large non-stick skillet over medium heat, add 1 tablespoon of olive oil, onions, and mushrooms. Saute until browned, stirring occasionally, about 5-8 minutes. Transfer the mushrooms to a plate and set aside.
Add 2 more tablespoons of oil and the risotto to the pan. Toast the rice until lightly browned.
Add the white wine and stir. Constantly stirring the risotto slowly is the secret to making this recipe and allows the liquid to be evenly absorbed.
Begin adding the chicken broth, one 1/2 cup at a time. Stir the rice for 3-5 minutes, then add more liquid. Repeat this process until all liquid is absorbed, about 25 minutes in total. Risotto should be creamy and tender but toothsome. If the risotto is still crunchy, add another half cup water or broth and stir.
Taste the risotto to check tenderness. Add the sautéed mushrooms and a large handful of fresh spinach to the skillet.
Stir the dish allowing the spinach to wilt. Add the butter and Parmesan cheese and stir until melted. This gives the dish a velvety, rich flavor. If you used water instead of chicken broth, you may need to salt and pepper the risotto to taste. Recipe makes 6 servings.