Set pressure cooker to "Saute". Heat olive oil. Add garlic and onion. Cook until softened and translucent. Add chicken broth, thyme, rosemary and basil. Season with kosher salt and ground pepper. Stir frequently.
Add chicken thighs into pressure cooker. Secure lid shut and change valve to "Sealing". Select "Manual" according to manufacturer's instructions. Set time on "high" for 12 minutes.
While chicken is cooking, whisk together cornstarch and heavy cream to make a slurry mixture. Set aside. Preheat the oven to broil on high.
After time is done, naturally release the pressure. Open lid and remove chicken thighs. Add them to a baking sheet. Place chicken into oven to broil on high, about 8-10 minutes.
While chicken is broiling, set pressure cooker to "Saute". Pour cornstarch slurry mixture into pot. Stir frequently until sauce has thickened. Add butter until melted.
Remove chicken from oven. Serve immediately. Top chicken with creamy lemon sauce.
To make meal complete, add a side of chicken-flavored rice and fresh steamed broccoli.