In a pan over medium-high heat, stir ground beef, garlic powder and 1 teaspoon salt until beef is crumbly and well browned, 6 to 8 minutes.
With a large slotted spoon, push beef mixture to one side of pan and tilt pan so liquid runs to opposite side.
Stir flour into liquid until well blended, then mix with beef mixture.
Add 2 cups water, black beans (or kidney beans) if using, and dried chilies; stir until mixture boils and thickens, about 8 minutes.
Spread about 1/3 cup of Fritos in each of six individual sized bowls and sprinkle chopped onion equally on top.
Divide chili equally among the bowls and top with cheese, lettuce and tomato.
Add more salt to taste if desired.
NOTE: For large party gatherings, I usually triple the recipe and prepare this buffet style for each person to "build your own" Frito Pie. For diehards, you must have sliced fresh jalapenos as a garnish, too!