Grill steak, seasoning with salt and pepper. Let steak rest for 10 minutes and cube into ½” bite size pieces. Reserve.
Halve avocado, peel and remove seed, cut in 1/2” bite size pieces, squeeze with lemon and reserve.
Cut cherry tomatoes in half, reserve.
Chop onion in ½” dice, reserve.
Gently combine all ingredients, plate and serve.