Grilled Chicken Sandwich Recipe

Combine mayonnaise, basil leaves, lemon juice, grated Parmesan, minced garlic, and a pinch of salt and pepper in a small food processor or blender.

Blend until smooth, streaming in the 2 tablespoons extra-virgin olive oil to emulsify. Taste and adjust seasoning with additional salt or lemon if needed. Chill until ready to assemble (at least 15 minutes).

Preheat oven to 400°F (200°C). Slice the beefsteak tomato into 1/4-inch rounds and place on a rimmed baking sheet lined with parchment.

Brush both sides lightly with 1 tablespoon olive oil and sprinkle with 1/4 tsp garlic powder, 1/4 tsp salt and a pinch of black pepper.

Roast in the oven for 12–15 minutes until slightly softened and edges begin to caramelize. Remove and let cool slightly. (If using pre-roasted or store-bought tomatoes, skip this step.)

Cut peeled russet potatoes into very thin shoestring fries (use a mandoline or sharp knife). Immediately place cut fries in a large bowl of cold water and soak for 20–30 minutes to remove starch.

While fries soak, heat beef tallow in a heavy-bottomed pot or deep fryer to 325°F (163°C). Dry the potatoes thoroughly with clean kitchen towels or paper towels.

Fry the potatoes in batches for 3–4 minutes until just tender but not browned. Remove to wire rack or paper towel-lined tray. Increase oil temperature to 375°F (190°C).

Return fries to hot tallow in small batches and fry for 1–2 minutes until golden and crisp. Drain on paper towels and immediately season with 1 tsp salt and 1/2 tsp freshly ground black pepper. Keep warm while assembling sandwiches.

Pound chicken breasts to an even thickness (~1/2 inch) for even cooking. Pat dry.

In a small bowl, mix 1.5 tsp kosher salt, 1 tsp black pepper and 1/2 tsp garlic powder. Rub both sides of the chicken breasts with 2 tablespoons olive oil and season evenly with the spice mix.

Preheat a grill pan or outdoor grill to medium-high heat (about 425°F/220°C). Oil the grates lightly or brush pan with oil.

Grill the chicken 4–6 minutes per side (depending on thickness) until internal temperature reaches 165°F (74°C) and nice grill marks form. During the last minute of cooking, top each breast with two slices of Havarti cheese, close grill lid or cover pan to melt cheese.

Meanwhile, lightly toast sourdough slices on the grill or in a toaster until golden (about 1–2 minutes per side).

Spread about 1 tablespoon of basil pesto aioli on the bottom slice of each toasted sourdough, and 1 tablespoon on the top slice.

Place the grilled chicken (with melted Havarti) on the aioli-coated bottom slice. Top chicken with 1/2 cup oven-roasted beefsteak tomato slices, a generous handful (about 1/2 cup) baby spinach, and 6 fresh basil leaves.

Close sandwich with the top slice of sourdough, press gently, and slice in half if desired. Serve immediately with beef tallow shoestring fries.