In a small bowl, combine first 5 ingredients.
If desired, insert lemon, onion and garlic into the cavity of the chicken.
Brush outside of chicken with 1 tablespoon oil and sprinkle with herb mixture.
Select saute setting on a 6-qt. electric pressure cooker.
Adjust for medium heat; add remaining 1 tablespoon oil.
When oil is hot, sear chicken, breast side down, until browned, 4-5 minutes.
Press cancel; remove chicken.
Place trivet insert and broth in pressure cooker.
Place chicken on top of trivet.
Lock lid; close pressure-release valve.
Adjust to pressure-cook on high for 25 minutes.
Allow pressure to release naturally
Gravy:
Pour drippings and loosened browned bits into a 2-cup measuring cup.
Skim fat, reserving 4 tablespoons (if less than 4 tablespoons fat, add enough melted butter to the fat to total 4 tablespoons).
Add enough broth to the drippings to measure 2 cups.
In a small saucepan, combine flour and reserved fat until smooth.
Gradually stir in the drippings mixture.
Stir in the thyme, sage, salt and pepper.
Bring to a boil; cook and stir until thickened, about 2 minutes.