Chill 4 salad plates.

Preheat oven to 250 degrees F.

Prepare mushroom marinade: Combine diced garlic, olive oil, balsamic vinegar, salt, and pepper in a bowl.

Coat mushrooms with marinade.

Roast mushrooms, bottoms down, on a sheet pan for 45 minutes, or until tender and sweet.

Remove mushrooms from oven and dice.

Reduce balsamic vinegar to a glaze in a saucepan over low heat.

Julienne sweet onion and shock in ice water for 4 minutes. Strain and set aside.

Combine peppercress and baby lettuce in a bowl.

Season shrimp with salt and pepper.

Sear shrimp in olive oil in a hot pan. Set aside.

Prepare vinaigrette: Combine Banyuls vinegar, mustard, lemon juice, salt, and pepper in a bottle.

Shake well until salt is dissolved.

Add grapeseed and canola oil and shake again.

Combine tomatoes, chives, shallots, haricots verts, and shrimp with the lettuce mixture.

Mix gently to combine.

Add vinaigrette to lightly coat ingredients.

Arrange salad on chilled plates, creating a layered peak.

Garnish with balsamic syrup and serve.