Set a small braiser or medium-sized Dutch oven over medium heat. Add the butter and olive oil, allowing them to melt together until they gently sizzle. Add the shallot, fennel, diced beet, and ½ teaspoon of the salt. Sauté the vegetables, stirring frequently, for about 3 minutes, or until they release their aroma and begin to soften.

Pour in the arborio rice and stir thoroughly, coating each grain in the butter-oil mixture. Let the rice toast slightly, stirring often, for another 3 minutes until the edges of the grains appear translucent.

Deglaze the pan with the sherry vinegar, scraping the bottom to lift any flavorful bits. Add the remaining salt and begin gradually adding the warmed chicken broth, one cup at a time. Stir continuously, allowing the rice to absorb almost all of the liquid before each new addition. Continue this process until the rice is tender and creamy, yet still has a slight movement when spooned onto a plate—this should take around 20 minutes.

Fold in the grated Parmesan cheese and stir until fully melted and incorporated, enriching the risotto with a smooth, savory finish. Spoon the risotto into serving dishes and top with crumbled Gorgonzola dolce for a rich, tangy contrast. Serve warm and enjoy the vibrant flavors.