Dice two medium onions into fairly small pieces, then heat olive oil in a large heavy pan and start to cook the onions over low heat.

Let onions cook at low heat stirring every few minutes until onions are nicely browned and caramelized, about 30 minutes.

Don’t rush this step and be sure onions don’t burn or they will be bitter.

After onions cook for 15 minutes, start preheating oven to 375F/190C.

Add minced garlic and dried thyme to the onions and cook about 2 minutes more.

Mix together eggs, sour cream, horseradish, and Worcestershire sauce.

Put ground beef into a bowl and let it come to room temperature.

When onions are done, add Flaxseed Meal (affiliate link) and onion-garlic mixture to the meat and season with salt and fresh ground black pepper.

Add egg/sour cream/horseradish/Worcestershire sauce mixture to meat. (Adding this on top of the onions will help cool them.)

Use your hands to gently combine until all the ingredients are well-mixed.

Form the meat mixture into a loaf and place on top of the broiler pan (or roasting pan of your choice.)

I like to make criss-cross slits on top of the meatloaf, but it's completely optional!

Bake meatloaf at 375F/190C for about 75 minutes, or until meat reaches 55-160F on an Instant Read Meat Thermometer (affiliate link).

Let meatloaf cool for 10-15 minutes before cutting; then stir together sauce ingredients and serve the meatloaf with Sour Cream-Horseradish Sauce if desired.