• Spray slow cooker with non-stick cooking spray. Pour beef broth in the bottom of the slow cooker.
• Place steak in the slow cooker and top with onion slices.
• In a small bowl, mix together olive oil, garlic, oregano, salt, pepper, and lemon juice.
• Pour on top of meat and place lid on top of slow cooker. Cook on low for 7-8 hours.
• When finished cooking, place meat on a pita and top with shredded lettuce, tomatoes, and sliced cucumbers. Drizzle with homemade Tzatziki sauce.

Tzatziki instructions:

• Strain yogurt using a cheesecloth over a bowl (if you don't have that, a strainer lined with a coffee filter will work) for a couple of hours (I let mine strain for about 6 hours) or overnight to get out as much moisture as possible (I know that this step sounds funny, but I promise that if you don't do it, your sauce will be runny and not as delicious).
• Shred or grate the cucumbers and blot them with a paper towel to get rid of as much moisture as possible.
• Mix together the strained yogurt, shredded cucumbers, garlic, vinegar and lemon juice. Add dill and salt and pepper to taste. Keep in the fridge until serving (let the flavors come together for about 30 minutes before serving).