What's for Dinner Wednesday~Cast-Iron Burgers and Fries

This recipe comes from one of my very first Gluten Free Cookbooks, The Cooking Light Gluten Free Cookbook.  I love that there are several recipes that are dairy free as well now that #2 and I can no longer eat/drink dairy (me-Cow's milk products, she-all animal milk).

Cast Iron Burgers and Fries

Patties:
1 lb ground sirloin (we use grass fed beef)
1/4 tsp kosher salt (we use sea salt)

Horseradish Spread:
1 TBS canola mayonnaise (we use Follow Your Heart Vegan Mayo-Dairy and Soy Free)
1 TBS Dijon Mustard
1 TBS prepared horseradish
2 tsp ketchup

Relish:
2 applewood-smoked bacon slices, chopped (we used the Hormel Natural Bacon-GF we had on hand)
3 C vertically sliced yellow onion (we use our mandolin for this)
1 TBS finely chopped fresh chives
1 tsp Worcestershire sauce (check for GF)
1/4 tsp freshly ground black pepper (we use white as I cannot have black)

Remaining Ingredients:
Cooking spray (we prefer coconut oil)
4 (2.8 ounce) gluten-free hamburger buns, toasted (we use Pure Knead buns-free of top 8 allergens as #2 cannot have eggs, found at our local Kroger)
4 green leaf lettuce leaves
4 (1/4 inch thick) slices tomato

*we omitted the lettuce and tomato (the onion/bacon mixture is plenty)

To Prepare:

1. To prepare the patties, divide beef into 4 portions, lightly shaping each into a 1/2-inch thick patty.  Sprinkle evenly with salt. Cover and refrigerate 30 minutes.
2. To prepare horseradish spread, combine mayonaise and next 3 ingredients in a small bowl. Set aside.
3. To prepare the relish, cook bacon in a large nonstick skillet over medium-low heat until crisp. Remove bacon from pan. Add onion to drippings in pan; cook 15 minutes or until golden brown. Combine bacon, onion mixture, chives, Worcestershire sauce, and pepper in a small bowl.
4. Heat a large cast-iron skillet over medium-high heat. Coat pan with cooking spray. Add patties; cook 2 minutes on each side or until desired degree of doneness. Spread 1 1/2 teaspoons horseradish spread on cut side of each bun half. Top bottom half of each bun with 1 lettuce leaf, 1 tomato slice, 1 patty, 1/4 cup relish,and top half of bun.

We served good old OreIda seasoned fries (gluten free).