Heat a large skillet over medium heat and add the butter. Once melted, stir in minced garlic and cook for about 1 minute until fragrant. Add the lobster tails, cooking for approximately 5-7 minutes until they turn bright red and are opaque. Remove from heat, chop the lobster into bite-sized pieces, and set aside, ensuring to keep the melted buttery goodness for the risotto.

In a separate saucepan, heat the warm seafood broth over low heat. In a large pot, sauté diced onions in the remaining butter until translucent, about 3-4 minutes. Add the Arborio rice, stirring constantly for 2 minutes, to toast the rice lightly.

Pour in the dry white wine and stir until almost completely absorbed. Then, start ladling in the warm broth, 1/2 cup at a time, stirring frequently until fully absorbed, about 18-20 minutes total.

Once the risotto is creamy, remove from heat. Stir in the freshly grated Parmesan cheese, lemon juice and zest, and reserved lobster butter until fully incorporated.

Gently fold the cooked lobster pieces into the risotto and allow it to heat through for about 1-2 minutes before serving.