Cook and stir the ground beef, onion, and garlic together in a large skillet over medium-high heat until the beef is completely browned; drain fat from the skillet.
Stir the taco seasoning mix and water into the beef mixture; bring to a boil, reduce heat to medium-low, and cook at a simmer, stirring occasionally, for 5 minutes.
Preheat an oven to 350 degrees F (175 degrees C).
Place the prepared pizza curst on a baking sheet.
Blend the diced tomatoes with garlic and onion, salsa, and cilantro in a blender until smooth.
Spread the refried beans in an even layer on the prepared pizza crust, leaving a border of about 1/2-inch uncovered around the outside.
Spread about 1 cup of the diced tomato mixture over the refried beans in an even layer; reserve the remaining sauce.
Scatter the ground beef mixture over the layer of sauce.
Cover the beef with 1 1/2 cups Mexican-style shredded cheese blend.
Bake in the preheated oven until the cheese is bubbly and the edges of the crust are golden brown, 15 to 20 minutes; set aside to cool 5 minutes.
Top the pizza with shredded lettuce, chopped tomatoes, black olives, green onions, and 1/2 cup Mexican-style shredded cheese blend. Serve with the reserved sauce, sour cream, and 1 cup salsa.
