Cook the tortellini according to package instructions.
Season the chicken breasts with salt and pepper.
Grill the chicken until cooked through, about 6-7 minutes per side.
Melt the butter in a large skillet over medium heat and sauté the garlic until fragrant.
Add the heavy cream and bring to a simmer.
Stir in the Asiago cheese until melted and smooth.
Combine the cooked tortellini with the Alfredo sauce, adding reserved pasta water as needed.
Slice the grilled chicken and serve on top of the tortellini.