If making aioli from scratch: In a small bowl whisk together 3 tbsp mayonnaise, 1 tsp maple syrup, 1 tsp Dijon mustard, 1/2 tsp lemon juice and 1/4 tsp minced garlic until smooth. Season with 1/8 tsp salt and a pinch (1/16 tsp) black pepper. Taste and adjust sweetness or acidity to balance. Reserve.

Prepare greens and tomato

Remove kale stems and tear leaves into sandwich-sized pieces (about 1 cup packed). Rinse and dry thoroughly. In a small skillet over medium heat add 1 tsp olive oil and when shimmering add kale. Sauté 30–45 seconds until bright and slightly wilted but still tender. Season with 1/8 tsp salt and a small grind of black pepper. Remove to a plate and keep warm.

Slice tomato into 1/3-inch rounds. Lightly season both sides with a pinch of salt (about 1/8 tsp) and set aside on paper towel to avoid soggy bread.

Toast roll and warm brisket

Halve the pain au lait horizontally. Optional: spread 1 tsp butter on cut sides. Place cut sides down in a skillet over medium heat or on a griddle and toast 1–2 minutes until golden. Remove.

Using the same skillet (wipe briefly if needed), add the 1/4 lb hand-sliced brisket in an even layer. Warm for 1–2 minutes per side until heated through and edges begin to caramelize. If the brisket is cold-smoked but not fully cooked, ensure it is heated safely through (internal temp as needed). Remove and keep warm.

Cook the egg

In the skillet over medium-low heat add a touch of oil or butter if needed. Crack the egg into a small bowl then slip into the skillet. Cook sunny-side up for about 2–3 minutes until whites are set but yolk still runny, or baste with a tablespoon of hot oil for about 30–45 seconds to finish the top if you prefer. Season with a pinch of salt and black pepper. For over-easy, gently flip and cook 15–20 seconds more.

Assemble sandwich

Spread about 1–1 1/2 tbsp maple aioli evenly on both the top and bottom cut sides of the toasted pain au lait (reserve any extra for another use).

Place one provolone slice on the bottom roll, then layer the warm brisket (all slices). Top brisket with the second provolone slice so it will soften against the warm meat.

Add the sautéed kale evenly over the cheese, then arrange the tomato slices on top of the kale. Gently place the cooked egg on top of the tomato. Finish with the top roll and press lightly to seat the components.

If desired, return the assembled sandwich to the skillet cut-side down and press with a spatula for 30–45 seconds to help the cheese melt and seal. Transfer to a cutting board, cut in half, and serve immediately.