Preheat oven to 400 degrees.

Place sliced sweet potatoes in a medium mixing bowl.  Add one tablespoon of the olive oil, one tablespoon of fajita seasoning and one of the crushed garlic cloves. Mix well. 

Transfer sweet potatoes to a large baking sheet and roast for 15 minutes. Save the bowl to use for remaining vegetables.

Place sliced onions and peppers in the mixing bowl.  Add one tablespoon of olive oil, one tablespoon of fajita seasoning and one of the crushed garlic cloves.  Mix well and set aside.

Stack the tortillas on a large sheet of aluminum foil, wrap them in the foil and set aside. 

Remove the baking sheet from the oven, flip the sweet potatoes and move them to one side of the baking sheet. 

Transfer the bell peppers and onions to the baking sheet and spread in an even layer.  Return the baking sheet to the oven and roast for an additional 12 minutes or until the potatoes are tender and vegetables are soft. Add the foil wrapped tortillas to the oven (directly on the oven grate is fine) and allow to heat while the vegetables are roasting. If you have room you can place the wrapped tortillas in the corner of the baking sheet. Meanwhile make the zesty lime sauce. 

Place the greek yogurt in a small bowl, add zest of one lime and squeeze lime juice into the bowl (about 1 tbsp).  Mix well and set aside.

When the vegetables and tortillas are ready, remove from the oven. Optional to leave the vegetables behind and broil for about 3 minutes to add some crisp. 

Transfer vegetables and tortillas to a serving tray, serve warm with the zesty lime sauce, sliced avocado and lime wedges. Additional topping options in notes below.