Vegetarian Grilled Zucchini Croque Mademoiselle

Preheat a grill or grill pan to high heat. Toss the zucchini lightly with olive oil, salt, pepper, and herbes de Provence. Grill until charred and cooked through, about 4 minutes per side. Set aside.

In a small saucepan, melt the butter.

Whisk in the flour and cook over low heat for 1 minute.

Whisk in the milk, and continue whisking until the mixture has thickened enough to thickly coat a spoon. Set aside.

Preheat broiler to high.

Spread one side of each slice of bread with butter.

Place 6 tablespoons grated cheese on un-buttered side of one slice of bread. Top with the zucchini, then top with 6 more tablespoons cheese. Close sandwich, buttered side out. Toast the sandwich in a nonstick skillet over medium heat until golden brown on both sides, about 3 minutes per side.

Place the sandwich on a foil-lined rimmed baking sheet.

Spread the top with the white sauce, then top with remaining 1/2 cup cheese. Broil until the cheese is toasted.

Serve immediately.