For your vegetarian friends buy off Amazon, a Bayou Classic 60k btu propane burner for $50 along with a $30 carbon steel wok.
Under high heat stir fry (outdoors only) sliced up cabbage, broccoli, carrots, celery, onions, garlic, along with any other veggies--ginger is a nice option as well. Throw in some deep fried tofu squares (pre-made and frozen). Pour in the right amount of soy sauce and lemon juice towards the end of the high heat fry to taste. Most delicious stir fry ever (you can change up your sauce & combination of vegetables). I never stir fry indoors anymore--which isn't actually frying but more like stir-braising.
Your friends, vegetarian or not, will be amazed at how powerful your outdoor wok is! It's very entertaining and I always have fun using it. Cooks literally in about 3 minutes with a full wok. It will be a real stir fry--vegetables will be vibrant in color with amazing texture. There will be lots of mallaird reaction and caramelization going on along with slight charring (yum)--with that grilled taste from smoking fat vapors.
UDS (30 Gallon Smoker & Grill named Emma), Bayou Classic Propane Burner (60K BTU), PGS K40