For chicken, I set my convection oven (a big, regular-sized oven, not an 'air-fryer') to 425, put the seasoned breasts on a slotted rack with drip-pan, and give them a light spray with canola or coconut spray oil. I put them in for 17 min., then start using a good meat thermometer to get them to 160F. Always nice and juicy when done.
Steaks are harder for me but preheat a cast iron skillet for 15 min in a 500F oven and sear stove top 2 min each side. Pop back in the oven for another 2 min and rest on a plate for at least 5 min. I always use the thickest stakes I can, thin ones are too hard to get to rare- or med-rare temp.