First, prepare the wheat berries.
Rinse them well under cold water and drain.
In a small saucepan, combine the rinsed wheat berries and 1 1/2 cups / 355ml of water.
Bring to a boil, then reduce the heat to a simmer.
Cover and cook for 30 minutes.
Once cooked, drain any excess water.
Lightly coat the insert of a 4 to 5-quart slow cooker with nonstick cooking spray.
Add the drained wheat berries, 1 1/4 pounds / 567g (20 oz) sliced mushrooms, vegetable broth, uncooked rice, chopped shallots, minced garlic, dried oregano, salt, and black pepper to the cooker.
Stir everything together, then cover and cook on the low setting for about 4 hours, or until the rice is tender and has absorbed most of the liquid.
Once the rice is tender, turn off the slow cooker. Gently stir in the shredded Asiago or Parmesan cheese and the cut-up butter until they are melted and the risotto is creamy.
Cover the slow cooker and let it stand for 15 minutes to allow the flavors to meld. If the risotto seems too thick, stir in a splash of additional warm vegetable broth until it reaches your desired consistency.
While the risotto is standing, prepare the mushroom topping. Lightly coat a small skillet with cooking spray and heat it over medium heat.
Add the remaining 1 cup / 70g (2.47 oz) of sliced mushrooms and cook, stirring occasionally, until they are tender and lightly browned.
Serve the creamy risotto in warm bowls.
Garnish each serving with the sautéed mushrooms, a sprinkle of chopped yellow sweet pepper, and a flourish of fresh parsley.
Sauté the shallots, garlic, and the 1 1/4 pounds (1814 g / 64 oz) of mushrooms in a skillet with a little olive oil until fragrant and browned *before* adding them to the slow cooker. This simple step deeply enhances their earthy, savory flavor.
Don't skip the 15-minute standing time! This is when the magic happens—the cheese and butter melt into the rice, creating a rich, luscious sauce. For an extra pop of brightness, stir in a squeeze of fresh lemon juice just before serving.
