1.Preheat oven to 375 degrees.

2.Line a rimmed baking sheet with parchment paper. With a pastry brush, brush olive oil on outside of each mushroom cap, and around the interior and edges. Set finished caps on lined baking sheet and set aside.

3.Over medium-high heat, brown ground beef in a large skillet until no longer pink inside. Carefully drain off excess fat and return to heat.

4.Add 2-3 T. taco seasoning mix and ½ cup water to skillet. Stir to distribute taco seasoning evenly. Cook on medium-high heat for 5-7 minutes or until excess water cooks down, stirring occasionally. Remove from heat and cool for a couple of minutes.

5.Divide the seasoned beef among the 6 mushroom caps. Add approximately 1 oz. of shredded Mexican cheese to each cap and top with sliced green onions.

6.Place baking sheet on middle rack of oven and bake for approximately 15 minutes, until cheese is melted. Remove from heat and cool for a couple of minutes before serving.

7.To serve, top with chopped tomatoes, avocado, additional cheese, and green onions. For added crunch, serve with baked sweet potato chips.