Preheat oven to 400F. Lay out a piece of parchment or aluminum foil on a baking sheet.
Bring a medium pan to medium high heat and add ~ 1 1/2 Tbsp olive oil. Add sliced onions and 1/4 tsp salt.
Cook ~25 minutes, stirring frequently, or until onions are brown and caramelized. Stir in thyme and remove from heat.
Slice the tomatoes and cut the cherry tomatoes in half. Lay out on a paper towel lined platter and sprinkle with salt. (This helps removes excess water).
Lay the thawed puff pastry on the lined baking sheet and roll out evenly with a rolling pin (sometimes you don't need to roll it out if it's already flat).
Pinch up or roll the edges to form a small crust.
Poke the pastry inside the crust with a fork several times.
Sprinkle 1/4 cup Parmesan cheese on the pastry. Spread the cooled caramelized onions on the Parmesan
Layer the tomatoes and sprinkle with goat cheese and remaining Parmesan cheese.
Bake ~ 20-25 minutes or until the edges are golden brown.
Place on a wire rack and let cool 10 minutes.
Garnish with basil and add salt to taste. Happy Summer Eating! Beckie
Notes
Let caramelize onions cool before adding to puff pastry.
If having problems with a soggy crust then pre-bake the crust for 10-15 minutes
Use roma tomatoes if crust is soggy.
Make tarts smaller or individual size if you want to maximize crispy crust.