To begin the bread, using a wooden spoon, combine the bread flour, water, instant yeast, sugar and salt in a bowl of a stand mixer.
Knead the dough with a dough hook or paddle attachment for 8 to 10 minutes on medium speed; you are looking for a smooth elastic dough, which will have quite a runny consistency.
Add your oil, then continue to knead until all the ingredients are well combined.
You can do this process without a stand mixer by working the wooden spoon through the dough. Cover the bowl with a damp towel and rest in a warm area until the dough is doubled in size (1 to 2 hours depending on the temperature).
Preheat your oven to 390°F (200°C) and grease an 8 x 12–inch (20 x 30–cm) baking tray. Line the bottom of the tray with baking paper.
Once the dough has risen and is jiggly when gently wobbled, sprinkle the top with the rosemary, onion, sun-dried tomatoes and artichoke hearts. Evenly season the dough with pepper and salt, then top with a good drizzle of oil.
Bake in the oven for 30 to 35 minutes, or until the top of the focaccia is golden brown. Cool in the tin, then garnish with fresh thyme before slicing.