Place chicken breasts, oregano, salt, pepper, red pepper flakes, garlic, chicken stock, lemon juice and zest in a 6 or 8 quart Instant Pot. Mix together to combine and make sure that the chicken is not stacked on top of each other.
Cook on manual high pressure for 8 minutes and once done use the quick release function. Remove chicken, cover to keep warm and set aside.
Take 2 tablespoons of brine from the artichokes and place it in the pot. Drain the remainder of the brine and add artichokes and asparagus to the pot.
Cook on manual LOW pressure for 0 minutes. Use the quick release function when done.
Slice the chicken and divide on four plates along with artichokes and asparagus.
If desired you can thicken up the sauce at this point: Press the saute function. Add 1 teaspoon of arrowroot to a small bowl and scoop out some of the lemon liquid and whisk it with the arrowroot to create a slurry. Return it to the pot and let cook until it has thickened to your desired consistency. Drizzle over the chicken, asparagus and artichokes and serve with wedges of lemon.