Step 1: Prepare the Spinach Mixture

Start by defrosting the 10 oz box of frozen chopped spinach and squeezing out all excess liquid using a clean kitchen towel or your hands. This step ensures the mixture stays dry and prevents soggy burgers. In a large bowl, add the prepared spinach first.

Next, crack one egg into a separate small bowl to check it before adding to the mix. Grate one clove of garlic directly into the bowl for a fine paste that distributes flavor evenly without chunks. Grate half a small onion similarly to create a smooth paste that blends seamlessly and avoids raw onion bites.

Step 2: Season the Base

Pour in 2 teaspoons of Worcestershire sauce, which adds deep umami flavor without overpowering the turkey. Sprinkle in salt and pepper to taste, starting conservatively since you can adjust later. Add 3 tablespoons of bread crumbs initially; these act as a binder while keeping texture light.

Drizzle 1 teaspoon of olive oil into the bowl to enhance moisture, crucial for lean turkey meat. Use a fork to mix everything together thoroughly until well combined. Mixing the seasonings before the meat prevents overworking the turkey, which can make patties tough.

Step 3: Incorporate the Turkey

Lightly oil a plate with olive oil to prevent sticking later. Add 1 pound of ground turkey or turkey breast to the bowl. Gently combine with a fork, working quickly to avoid compacting the meat and ensuring a tender result.

Divide the mixture: score into halves for four large burgers or quarters for eight smaller ones. Form patties by grabbing portions and shaping lightly. For smaller burgers, this yields quicker cooking and easy freezing of extras.

Step 4: Shape the Patties

Place each patty on the oiled plate. Press a gentle indent in the center of each with your finger; this prevents puffing during cooking and keeps them flat. Drizzle tops lightly with more olive oil for non-stick grilling.

If making eight, cook four now and freeze the rest flat on a tray before bagging. Smaller patties cook faster and stay moist, ideal for weeknight meals. Handle minimally to preserve juiciness from the spinach and oil.

Step 5: Preheat and Grill

Preheat your grill to high heat for beautiful marks and even cooking. Place patties on the hot grill without crowding. Avoid touching them initially; they release naturally when ready to flip, usually after 4 to 5 minutes for small patties.

Close the lid to cook evenly. Check edges for whiteness around the sides as a doneness cue without cutting, which releases juices. Flip once and cook the second side 3 to 4 minutes more until fully cooked through.

Step 6: Make the Lemon Mayo Topping

While burgers rest, mix ¼ cup mayo with zest and juice from half a lemon in a small bowl. Season with salt and pepper to taste. Stir until smooth; it may look loose but spreads perfectly thin.

Slice fresh tomatoes thinly. Toast hamburger buns on the grill edges for crispness. This topping adds bright, refreshing contrast to the savory patties.

Step 7: Assemble and Serve

Spread a thin layer of lemon mayo on the toasted bottom bun. Layer a tomato slice, then one burger patty. Cut patties in half if desired to showcase the spinach-speckled interior.

Top with the bun lid and serve hot. The combination delivers balanced flavors: moist turkey, veggie nutrition, tangy mayo, and fresh tomato. Enjoy immediately for best texture.