-
In a large mixing bowl, whisk together warm water, yeast, and sugar. Set aside for 5 minutes until mixture foams on top.
-
Mix in oil and egg. Add flour and 1/4 teaspoon salt.
-
Knead together for about 5-8 minutes on a lightly floured surface until dough is smooth.
-
Place dough in an oiled bowl and cover loosely with plastic wrap. Set aside in a warm area for 1 hour until doubled in size.
-
Preheat oven to 400°F.
-
Roll out dough into a 13-inch circle.
-
Transfer to an 11-inch tart pan, allowing sides to hang over the edges.
-
Press sides into tart pan. Roll a rolling pin over the top of the tart pan to cut off overhanging edges of dough and discard.
-
Spread mustard onto the bottom of tart crust.
-
Cover with concentric circles of sliced tomatoes.
-
Sprinkle olives, thyme, pepper and remaining salt on top.
-
Bake in a 400°F oven for 30 minutes.
-
Cover with cheese and continue baking for 5-10 more minutes until melted and golden brown.