Bring chicken stock to a simmer in a medium saucepan over medium heat. Once simmering, reduce heat to low, and keep warm.

In a large, heavy-bottom pot, warm 1 tablespoon olive oil, and 1 tablespoon butter over medium heat. Add the onion along with a pinch of salt, and cook until the onion is tender but not browned (5 to 6 minutes). After 3 minutes add the garlic and lemon zest. Stir in the rice and cook for 2 minutes, then add the white wine and cook for 1 more minute. Add 1 cup of warm chicken stock and a pinch of salt, and cook, stirring occasionally, until all of the liquid has been absorbed. Continue adding warm chicken stock 1/2 cup at a time, waiting until the stock is absorbed before adding again, and stirring frequently to make sure the bottom doesn’t burn. Continue until the rice is cooked through, but still al dente, about 30 – 35 minutes total. You may not use all of the chicken stock.

While the risotto is cooking, warm remaining 2 tablespoons olive oil in a large skillet over medium heat. Add asparagus and cook, stirring occasionally, until just tender (4 to 5 minutes). Take off the heat and set aside.

To serve, spoon risotto in a shallow bowl and top with sautéed asparagus, a scattering of chopped tarragon, a sprinkling of Parmesan cheese and a few turns of black pepper.