Combine first 4 ingredients in a zip-top plastic bag and shake to mix. (I like to double first 4 ingredients because it makes more gravy, yummy!) Add beef cubes and shake to coat.
Brown beef in hot oil in Dutch oven or large pot, stirring often. Add onion and cook until tender. Dissolve bouillon cubes in boiling water and add to beef mixture. Cover, reduce heat, and simmer 2 hours, stirring occasionally. If water evaporates too quickly add more water/bouillon cube mixture.