Pickle the onions: Pack your thinly sliced red onions into a jar. In a measuring cup add vinegar, sugar, salt, and hot water together. Stir to combine. Pour over onions until fully submerged. Close the jar and allow to sit on the counter for one hour to marinate. ** Pickled red onions can be refrigerated for up to 3 weeks.
Make the aioli: To a small bowl add mayo, garlic, lemon juice, pepper, and salt and mix until smooth. Taste and adjust if needed. Set aside.
In a bowl, mix the Jennie-O ground turkey with garlic powder, oregano, smoked paprika, salt, and pepper. Make 8 small turkey balls and smash each one on the back of a small tortilla. Smash the mixture to the edges of the tortilla because the turkey will shrink a bit.
Heat a large skillet or griddle over medium-high with a little olive oil or non-stick spray.
Cook turkey-side down for 3–4 minutes until golden and cooked through, then flip and toast the tortilla side for one minute more.
Add pickled onions, cucumber slices, feta, and herbs. Drizzle with garlic aioli and serve.