Preheat oven to 375F. Line a baking sheet with parchment paper and set aside.
Add the shredded cheese over the top of the dough. Scatter the onion, red pepper, and sausage evenly over the top of the cheese. Make four 2-inch balls of crumpled tinfoil and lightly grease them with some olive oil. Lightly press the balls into the dough in 4 places (I go by each side, but not too close to the edge) to make a few small wells. Transfer to the oven and bake for 18 minutes.
If you prefer a more well-done yolk, pull the focaccia out of the oven 4 - 5 minutes earlier in step 4 and add them back to the bake time in step 5.
Recipe by Zest & Lemons