Clean, wash and thinly slice the rhubarb. Bring butter, sugar and vinegar to the boil. Simmer at low heat for about 5 minutes. Add rhubarb and peppercorns, bring to the boil again. Remove the pot from the heat, cover and let it simmer for 3-4 minutes.
In the meantime dab steaks dry. Heat 2 tablespoons of oil in a frying pan. Fry the steaks for 2-3 minutes on each side. Season with salt and pepper and remove. Wrap in aluminium foil and let it rest for about 10 minutes.
Wash and chop the thyme and add to the rhubarb. Season to taste with salt and pepper.
Press the garlic clove flat and fry in 2-3 tbsp. oil. Fry the baguette slices on each side until golden brown. Arrange steaks and rhubarb sauce. Add garlic bread.