Place a large pot of water to boil over high heat. This is what you'll be cooking your jumbo shells in.
While your water is coming to a boil, season your chicken breast with the salt and pepper on both sides.
Heat a large heavy-bottomed skillet over medium-high heat. Add your avocado oil to the skillet.
Once the oil begins to shimmer, place your chicken in the skillet. Cook on both sides (only flipping once) until the internal temperature reaches 160°F. Remove the chicken from the skillet and set aside to rest.
Turn the burner down to the lowest heat setting and add your garlic. Sauté for 1 minute, just until fragrant. Pour in your chicken stock.
Bring the mixture up to a simmer and add in the cream cheese. Stir until melted. Once the cream cheese has melted, remove from burner and set aside.
When your pasta water comes to a boil, add in your shells. Only cook until al dente, about 6-7 minutes.
Drain the pasta and set aside to cool.
Chop up your chicken into bite size pieces and add to a mixing bowl.
Add ricotta, oregano, basil, and parsley to the bowl with the chicken. Mix until combined.
In a 9x13 baking dish, pour about 1/2 cup of sauce. Spread to cover the bottom of the dish.
Take each jumbo shell and fill it with the chicken ricotta mixture and place open side up in the baking dish. Repeat until all of the shells are filled.
Pour the remaining sauce over the top of the shells.
Sprinkle the parmesan cheese across the top of the shells.
Bake in the oven for 15-20 minutes until it is hot and bubbly.
Serve warm with a sprinkle of basil and a side of garlic bread!