Peel and chop the onions. Cut bacon into strips. Heat oil in a pan and fry bacon and onions for 7-8 minutes, turning them over. Add sugar and caramelize for 2-3 minutes while stirring.
Stir in tomato paste, braise briefly and deglaze with vinegar. Add cherry tomatoes and 50 ml water, bring to the boil and simmer over medium heat for 15-20 minutes. Stir in between. Finally, season the bacon jam with pepper, pour into glasses, allow to cool and chill.