Trim the leek, removing the tough end and the green stalk. Slice in half lengthwise, then into half moons. Wash thoroughly to remove any dirt.
Wash and slice off the ends from one large apple. Using a spiralizer kitchen tool, spiralize the apple into thin noodles. Alternatively, you can thinly slice if a spiralizer isn’t available. Place apple noodles in a bowl with a teaspoon of lemon juice, to prevent browning.
Heat olive oil in a medium skillet over medium-high heat. Add the leek slices and stir to coat. Cook for 2-3 minutes, until softened.
Add the apple noodles to the skillet, tossing together with the leek slices to combine (tongs are useful for this). Cook 1-2 minutes until softened. Remove from heat.Slice 4-5 thick slabs of Brie cheese. Finely chop walnuts. Set aside.
Lightly toast your choice of gluten-free bread.
Assemble the breakfast toast. First, layer the Brie over each slice of toast. Top with a generous amount of Bonne Maman Apricot Preserves. Next, layer a pile of cooked apple and leek over top. Garnish with crushed walnuts.