Combine water, soy sauce, garlic, honey, and tapioca starch in a small saucepan over low heat. Bring to a boil. Simmer, stirring constantly, until sauce thickens, about 3 minutes. Remove sauce from heat and let cool.
Pour cooled sauce into a blender; pulse a few times to puree the garlic.
Mix beef with salt, 1 teaspoon black pepper, and onion powder in a bowl.
Heat olive oil in a large skillet over medium-high heat. Add the beef; cook until heated through, 2 to 3 minutes. Add the remaining 1/2 teaspoon pepper, rice, peas, corn, and butter. Cook and stir until beef is no longer pink and mixture is heated through, 7 to 10 minutes. Serve with the garlic sauce.