Prep all ingredients according to the ingredient list.
Season the ground beef with chili powder, ground cumin, garlic powder, salt, and black pepper.
Heat oil in a skillet over medium heat. Saute the ground beef, breaking it into small pieces, until fully browned. Remove from heat.
Warm the soft taco shells in a pan over medium heat until pliable on both sides.
Fill each taco shell with beef. Top with diced onion, diced tomatoes, shredded Monterey Jack cheese, and lettuce.
To make the guacamole, mash the avocados in a bowl until smooth. Add chopped cilantro, lime juice, garlic powder, salt, and black pepper. Stir until well combined.
For the chia fresca, combine combine all the ingredients. Let sit 5 minutes until the chia seeds bloom and slightly thicken.
Serve the tacos with tortilla chips and guacamole alongside sparkling chia fresca.