#1 Process the onion in a food processor for 10 to 15 seconds and turn into the center of a tea towel. Gather up the ends of the towel and squeeze until almost all of the juice is removed. Discard juice #2 Return the onion to the food processor and add the lamb or beef, garlic, marjoram, rosemary, salt & pepper, and process until it is a fine paste, approximately 1 minute. Stop the processor as needed to scrape down sides of bowl. Place the mixture in a pan over medium-high heat and brown until no longer pink #3 Slice or crumble and serve on one half of an English Muffin. Fold over and secure with a wooden pick #4 Top with tzatziki sauce (see below), chopped onion, tomatoes and feta cheese #5 For Tzatziki Sauce: place the yogurt in a tea towel, gather up the edges, suspend over a bowl, and drain for 2 hours in the refrigerator #6 Place the chopped cucumber in a tea towel and squeeze to remove the liquid. Discard liquid #7 In a medium mixing bowl, combine the drained yogurt, cucumber, salt, garlic, olive oil, vinegar, and mint #8 Serve as a sauce for gyros.