Mise en place - Pour the stock into a medium pot and heat it on the back burner, at not quite a simmer - you're just keeping it warm. Peel and finely dice the onion. Peel and smash the garlic, then give it a rough chop.
Sauté the onions and garlic - Add butter and oil to a large skillet over medium heat. Add the onions and cook until just tender, then add the garlic. Cook 1 minute longer.
Add the rice and simmer - Add the rice and toss to coat, then stir until each grain of rice becomes just a bit translucent. Add the wine and stir until it is fully absorbed. Add one ladle of stock at a time, stirring after each addition, keeping the risotto at a simmer. Repeat until you have added most of the stock, about 20 minutes or so.
Finish - Add the baby spinach when you add the last ladle of stock, and once the spinach is wilted, add the cheese. Your risotto should be creamy and thick at this point, but if it's a bit tight, add a dash of heavy cream. Enjoy!