Heat olive oil and butter in a large skillet over medium heat. Once the butter melts, add minced garlic and a pinch of salt. Sauté for about 5 minutes, stirring frequently, until fragrant.

Pour in the heavy cream and remove the pan from heat momentarily. In a small bowl, whisk together the flour and water to create a smooth slurry. Slowly add the slurry to the cream, whisking quickly to avoid lumps. Return the skillet to the heat and let the mixture simmer for 10 minutes, stirring occasionally, until the sauce thickens.

Once the sauce is creamy and thick, stir in the shredded Asiago cheese until fully melted and smooth.

Add the cooked penne pasta to the skillet and toss until well-coated in the sauce. Taste and adjust salt as needed.

Plate the pasta immediately, and garnish with extra Asiago cheese or a sprinkle of parsley for a fresh touch.