At its fundamental core, risotto is about making rice slowly absorb liquids to create a creamy, flavorful dish.
Heat half the olive oil in a 2-quart saucepan over medium-low heat. Add the cubed squash and sauté for five to ten minutes, until it just begins to brown. Remove from pan and set aside. Sauté the remaining olive oil and chopped leeks, along with a pinch of sea salt, for five minutes, until tender and translucent. Add the rice and stir until the grains are warm and covered with fat. As you pour in the liquid, you’ll want to keep stirring. Add one cup of stock. Cook at a gentle simmer until mostly absorbed. Add a second cup of stock and the squash. Once that stock is absorbed, the grains should be mostly tender. Continue to add a quarter cup of stock at a time until the grains are ready. They should be al dente – with a bit of resistance at the center. The risotto will continue cooking once it comes off the heat. Stir in the cheese, if using, and serve.