Wash and deseed all vegetables. Make small cups out of each except for the onions and the chard.
In a larger bowl, combine all filling ingredients, and mix with your hands until incorporated.
Bring water to boil in a small pot and add onions. Boil for 5 minutes and take out. Dip chard into boiling water for 30 seconds and take out. Cool onion, and press lightly in the middle until it falls out and you're left with a few outside circles.
In a large pot, place all sauce ingredients. Bring to boil and turn off.
Stuff all vegetables with the filling. Stuff chard as you would stuff cabbage leaves by placing a small amount of meat in the middle, folding the sides in and toward yourself. Place in a deep pan. Heat oven to 395°F.
Cover pan, place in the oven and bake for 1 hour. Take the lid off, and bake another 10 minutes.