Do you know if they eat mushrooms?
Get four large portabella mushrooms. Remove the stems, wash and dry. Brush the outside with olive oil, sprinkle with salt and pepper (inside and out) and set aside.
Saute diced pancetta in olive oil if you are healthy or butter if you are me

Add about a tbsp. minced yellow onions, two chopped green onions and two crushed garlic cloves and sauté until transluscent.
Mix together a brick of softened cream cheese (I suppose you could also use goat cheese if you like the taste), the pancetta/onion mix, and about 1/2 cup shredded cheese (your choice, I like parmesan) and/or 2-3 tbsp. feta cheese, and 1/2 cup unseasoned fine bread crumbs. Add any other greens or veggies that appeal to you such as fresh baby spinach, minced red peppers, etc. Whatever tastes good together. Squeeze in juice from half a lemon. Season with salt and pepper, or fresh herbs, tasting as you go so you are sure it tastes good.
Press the fillings into the caps.
Sprinkle with more of the shredded cheese.
Sprinkle with olive oil and balsamic vinegar, or garlic lemon butter if you prefer
Cook on the grill until warm and oozy, or bake at 375 (covered for about 20 minutes) then uncovered for 10 minutes
Sounds and looks complicated but is very easy to do.
Is hearty enough to be an entrée
Play around with it ahead of time to get the flavors right.
Serve with a side like pasta or couscous.