Roast your garlic if it is not done already (see note).
Place the stock in a pot and heat over medium low. You want the stock to be warm when adding it to the risotto so that the temperature change does not affect the rice.
In a large pot over medium heat, melt 3 Tbsp of the butter. When melted, add the red onion. Cook until the onion is translucent but not yet browning, approximately 3-5 minutes.
Add the rice and garlic powder. Stir. Continue cooking to slightly toast the rice until it is just starting to show a little brown color, approximately 3-5 minutes.
Add the white wine to the pot. Cook until the rice is almost dry, where most of the wine has been absorbed.
Start cooking your Italian sausage while your risotto is going. Heat a medium saute pan over medium heat. When hot, add the sausage. Cook until browned, approximately 5-7 minutes. Flip and cook until the other side is browned and the sausage is cooked through, approximately 5 minutes more. Set aside.
Add 1/2 cup of stock to the rice. Stir continuously until most of the stock has been absorbed. Repeat this process one cup of stock at a time until the rice is cooked thoroughly. You want the rice to have just a little bit of bite left so that it is not completely mushy. Depending on your rice, you may need more or less stock for the right consistency so start tasting the rice after 4 cups have been added.
When your rice is cooked through, remove the pot from the heat. Add the rest of the butter, the Parmesan cheese, roasted garlic, and tomato paste. Stir to combine.
Taste the risotto and season with salt and pepper as desired. Serve with Italian sausage or other meat of choice if desired.