Toma'muse cake and onion | Stoffels Tomaten

Ingredients

• For the cake base
• 250 gr flour
• 125 gr butter
• 50 gr ground gruyere
• Pinch of salt
• For the filling
• 500 gr Toma'muse tomatoes
• 120 gr butter
• 1 kg sweet onion (finely chopped)
• 4 cloves of garlic (finely chopped)
• 1 teaspoon of finely chopped rosemary
• 100 gr gr grated gruyere
• Olive oil
• Pepper and salt