Grate and drain the cucumber for the Tzatitki (recipe below) the evening before as you marinate the beef.
Place sliced meat in Ziploc and put the Ziploc in a bowl. In a small bowl, add olive oil, garlic, salt, oregano, marjoram, pepper, allspice, and nutmeg. Mix together into a paste. Add the red wine vinegar, the lemon juice, and water and mix together.
Pour the marinade mixture over the beef and massage well, making sure that the meat is all coated. Pull up the Ziploc, expel as much air as possible and seal. Refrigerate overnight, turning several times if possible.
When ready to cook, add one cup of water to the instant pot, then add the trivet. Drain the meat and place on top of the trivet in a pile. Try to keep as much of the meat as possible on the trivet (try laying a few larger slices across on the bottom) but don’t stress if some falls through.
Set Instant Pot to high pressure, 7 minutes. When finished, allow to go to the keep warm setting for 10 minutes. Release any remaining pressure manually. Remove meat and set aside, lightly covered.
To steam Pita:
Use something to put the trivet back in the Instant Pot about three to four inches from the bottom; several balls of foil work well. Add the trivet on top. Wrap several pitas in a large, thin kitchen towel, wrapping around several times and making sure all is covered. Carefully place on the trivet, making sure that none of the towel touches the liquid.
Set Pressure to steam, one minute. When the pot begins to make noises and some steam is starting to come up around the back of the lid, push the cancel button and remove the pita. Remove towel and wrap in a dry towel to keep warm. Warning: some of the pita may be a little on the wet side so it’s a good idea to steam one or two extra.
To assemble Gyros, lay out a square of foil, put a pita on top. Spread a little Tzatziki down the center of a pita, add several slices of meat, top with more Tzatziki, slices of onion, tomato & lettuce. Wrap up with the foil and serve.
Grate the cucumber and drain through a fine-mesh sieve overnight in the fridge or place on a clean kitchen towel and wring the moisture out. Combine with the yogurt, garlic, olive oil, vinegar, salt and dill and stir to combine. Taste and adjust any seasonings and add additional olive oil if the mixture needs to be thinned.
Keywords: Beef, Cucumber, Greek, Instant Pot, Lettuce, pita, Red onion, Sandwiches, Tomatoes, Tzatziki, Yogurt