To start, add rice and about 2/3 of your broth to the rice cooker. Stir it well. Close the lid and cook for about 20 minutes. Use this time to prepare your other ingredients, like sautéing mushrooms and veggies.
After 20 minutes, open the lid and stir everything. Add your sautéed mushrooms and veggies, then the rest of your broth.
For a great risotto, keep an eye on it and stir often. It should be creamy but still have a bit of bite. Remember, it will soak up more liquid after you turn off the heat.
Notes
Let your risotto rest for a few minutes. This helps it soak up any extra liquid, making it just right.