You can put any vegetables you want on this tart. The only ones that need to be pre-cooked are the potatoes.

1 sheet puff pastry or 1 recipe for Shortcrust Pastry
3/4 cup mild goat cheese
1/4 cup half and half
1 egg
4 cloves garlic confit or roasted garlic (optional), squeezed out of skins
pinch of salt 
2 tablespoons dijon mustard
6 yukon gold potatoes, peeled, quartered, and pre-cooked
16 asparagus tips
big handful of cherry tomatoes
1/2 cup parmesan cheese, grated

Take pastry dough out of the fridge 10 minutes before rolling it out (30 minutes if it's been in the freezer). 

Preheat oven to 350°F.

With a standing mixture (or by hand), whip together goat cheese, half and half, egg, optional garlic confit, salt, and pepper.

On a floured surface, roll out dough until it's approximately 19"x 7".  Fold all four edges in about about 2 inches and press down to seal (it should look like a picture frame). Spread the bottom with a thin layer of mustard (but not up on the folded over edges). Follow in the same way with goat cheese mixture. Scatter potatoes, asparagus, and cherry tomatoes all all over the goat cheese mixture. I like the messy look but you can also choose to do a pretty pattern. Add more salt and pepper. Sprinkle parmesan cheese over the top of the tart. Sprinkle on more salt and pepper. And a bit of olive oil. 

Bake until and vegetables and edges are golden brown. The entire galette should be firm on the bottom. Test this by lifting up a corner. The galette shouldn't collapse down. It should lift up in one piece.