In a medium bowl, toss strips of beef with pepper and brown sugar, then toss with cornstarch until well-coated. Set aside.
In a large skillet or wok over medium-high heat, add 1 teaspoon oil and eggs. Cook until formed but still soft, then transfer to side dish.
Turn heat on high, then add a drizzle of oil and fry strips of meat until crispy. Don’t overcrowd the pan, so cook in two batches.
Remove the meat and set aside with eggs.
In same skillet over medium-low heat, add garlic, ginger, green onions, and red pepper strips. Cook 2-3 minutes until hot.
Add cooked wheatberries, soy sauce, vinegar, and sesame oil.
Add reserved cooked meat and eggs, then toss together and serve immediately while hot.