STEP 1 Cook pasta 2-3 minutes in boiling salted water. Reserve 1/2 cup of water.
STEP 2 Whisk together eggs and Parsesan, set aside.
STEP 3 Heat large skillet over medium heat, add bacon and cook until crispy, reserve excess fat.
STEP 4 Stir in garlic and onion, cook about 1 minute and reduce heat to low.
STEP 5 Stir pasta and egg mixture into pan and gently toss all ingredients together, add reserved pasta water in small amounts as needed until sauce coats noodles.