1. In a PADERNO Classic Non-Stick 1.3 L Sauce Pan, bring the stock to a boil over medium heat. Reduce heat to low; cover and keep warm.
2. Heat a PADERNO Classic Non-Stick 2.8 L Sauce Pan over medium-high heat; add the oil. Sauté the leeks until tender, 3 to 4 minutes.
3. Add the mushrooms; sauté 3 to 4 minutes. Add the garlic; cook, stirring 2 to 3 more minutes.
4. Add the rice; stir until grains are coated. Pour in the wine; cook until liquid evaporates.
5. Add enough of the warm stock mixture to just cover the rice. Bring to a boil; reduce heat to maintain a simmer.
6. When liquid is absorbed, add a large ladleful more warm stock mixture. Repeat process, adding a ladleful at a time and allowing liquid to be absorbed before adding more, until all stock mixture is incorporated and rice is tender but firm, 20 to 25 minutes.
7. Remove from heat; stir in spinach. Stir in the butter, cheese, lemon juice and thyme. Season to taste with salt and pepper.
Tip: Replace chicken stock with vegetable stock or broth for a meatless option.