Instant Pot® Chicken Saltimbocca

Place chicken breasts on a flat work surface. Slice horizontally through the middle, being careful not to cut all the way through to the other side. Open the 2 sides and spread them out like an open book. Season with salt and pepper. Open each butterflied chicken breast and sprinkle with sage. Add a slice of prosciutto and close each chicken breast. Dredge in flour.

Turn on a multi-functional pressure cooker (such as Instant Pot®) and select Saute function. Melt butter in the hot pot; add olive oil. Sear chicken breasts until golden brown, 3 to 4 minutes on each side. Remove and set aside.

Stir shallot and garlic into the hot pot and cook until softened, 5 to 7 minutes. Deglaze the pot with chicken broth, bringing to a boil while scraping the browned bits of food off the bottom of the pan with a wooden spoon. Stir in lemon juice and lemon zest. Turn off the pot.

Place a trivet into the pot and place chicken on top. Close and lock the lid. Select high pressure according to manufacturer's instructions; set timer for 5 minutes. Allow 10 to 15 minutes for pressure to build.

Release pressure using the natural-release method according to manufacturer's instructions for 15 minutes. Remove chicken and trivet and place chicken into a baking pan.

Combine water and cornstarch in a small bowl, creating a slurry. Set the Instant Pot® to Saute. Stir in cornstarch slurry and cook until sauce has thickened, about 5 minutes. Pour over chicken and top with mozzarella cheese.