Prep the chicken. Pat the chicken thighs dry, then season with salt and pepper.
Start the water. Set a pot of water on to boil.
Sear the chicken. Preheat a pan over medium heat and let it come fully up to temperature. Add the olive oil and coat the bottom of the pan. Quickly add the chicken and sear hard for 4-5 minutes per side. Remove to rest. It’s okay if the chicken isn’t cooked all the way through.
Brown the butter. Turn the heat down a notch below medium and add the butter. As it melts, scrape up all the browned chicken bits. Keep stirring until the bits and the butter turn golden brown, 3-4 minutes.
Add the aromatics. Add the shallot, garlic, and sage to the butter. Stir continuously and cook for another 3-4 minutes.
Deglaze. Scoop some hot pasta water into the butter and bring to a simmer. Reduce by half.
Finish the chicken. Cut the thighs into bite-size pieces and add them to the pan along with their juices. Cook the chicken through.
Cook the tortellini. Drop the tortellini into the boiling water and cook according to the package directions. Fresh tortellini should only take about 4-5 minutes.
Add the cream. Turn the heat down to medium-low. Stir in the heavy cream and simmer until the tortellini is done cooking.
Combine. Drain the tortellini, reserving some of the cooking water. Add the tortellini to the pan and stir. Add reserved water a little at a time until the sauce reaches your desired thickness.
Season. Add salt and pepper to taste.
Serve. Top with chili crisp, fresh sage, and shaved Parmesan.