For the pita chips preheat the oven to 400ºF. Line a baking sheet with parchment paper. In a small bowl, combine olive oil, cumin, chili powder, paprika, salt and cayenne pepper. Brush both sides of each pita with the olive oil mixture.
Cut each pita bread into 8 triangles. Place on prepared baking sheet in a single layer. Bake for 8 minutes, flip and bake 5-6 minutes more, until golden and crispy.
For the guacamole, mash avocados in a bowl and stir in red onions, cilantro, lemon juice, halved tomatoes, salt, cumin and chili powder.