Grilled Tomatoes with Caramelized Onions, Feta and Basil

Grilled Tomatoes with Caramelized Onions, Feta, and Basil (wedinfeb05)
**We use this as a BBQ side dish when we're at the beach -- goes great with turkey burgers!

2 tomatoes (largest ones you can find)
1 red onion, peeled and sliced into rings
1 pkg feta cheese
Fresh basil
Butter (for caramelizing)

Cook onions in butter over medium heat for about 20 minutes or until caramelized. In the meantime, heat the grill and slice the tomatoes into thick slices. Put the tomatoes on the grill (on foil if you can) and top with caramelized onions and feta cheese. Grill for 3-5 minutes. Remove from grill and top with basil.