Halve the 2 zucchini lengthwise and cut them into slices just under 1 cm thick.
Seed the 2 bell peppers and cut them into rough chunks.
Peel the 3 red onions, halve them and cut them into wedges.
Mix the cut vegetables and the 250 g small tomatoes in a bowl and season with plenty of olive oil, salt, pepper and oregano. Mix well and spread on a baking sheet lined with parchment paper, leaving the center free.
Cut 200 g pork belly bacon into strips, fry until golden brown in a nonstick pan, then take it out and spread it over the vegetables.
Preheat the oven to 180 °C (350 °F) conventional oven (top and bottom heat).
Pat the 2 pork tenderloins dry and season with salt & pepper.
Sear the tenderloins until crisp in the fat from the bacon. If you like, add one or two sprigs of rosemary or thyme to the pan.
Place the pork tenderloin in the center of the baking sheet and cook everything together on the middle rack of the oven for 40 min.
After the 40 min, take out the pork tenderloin, wrap it in aluminum foil and let it rest briefly.
Optional: heat 150 ml neutral oil for the fried capers. Drain 0.5 jar capers, rinse with water and dry with a kitchen towel. Then fry them in the hot fat over medium heat for approx. 2-3 min until they open up and are crispy. Carefully lift them out with a skimmer and let them drain on paper towels.
Slice the pork tenderloin diagonally and serve with the vegetables and the pan juices. Garnish with the capers if you like.