In a large bowl, whisk together the balsamic vinegar, olive oil, honey and smashed garlic. Season with salt and pepper.

Place the portobello mushrooms in a resealable plastic bag and pour the marinade over the mushrooms.

Marinade for 1 to 2 hours.

Preheat a grill pan over medium-high heat or prepare an outdoor grill.

Remove the mushrooms from the marinade and reserve the marinade.

Season the mushrooms with salt and pepper and drizzle with a bit of olive oil.

Place the mushrooms on the grill and cook for 2 to 3 minutes per side, or until tender.

Transfer the cooked mushrooms to a serving platter.

Heat a large saute pan over medium-high heat and add 2 to 3 tablespoons of olive oil.

Add the sliced garlic and raisins and saute for about 1 minute.

Add the chili flakes.

Toss in the shrimp and season with salt and pepper. Toss to coat in the garlic and raisin mixture.

Cook the shrimp for about 2 minutes, until just turning pink.

Deglaze the pan with about 1/4 cup of the reserved marinade.

Add the spinach and season with salt and pepper. Toss to coat.

Cook the spinach for about 30 seconds, until wilted.

Pour the shrimp and spinach mixture on top of the plated portobello mushrooms.

Garnish with the chopped chives and serve with honey mustard and lemon wedges.