Heat olive oil in a pan over medium until shimmering. Add onion and cook for 3 minutes until softened and slightly translucent. Stir in garlic, oregano, and red pepper flakes, cooking until fragrant, about 30 seconds. Add tomato paste and cook for another minute, stirring constantly to deepen the flavor.

Pour in crushed tomatoes and wine, scraping up any bits from the pan. Season with salt and pepper, then let simmer for 20-30 minutes, stirring occasionally. The sauce should thicken slightly as it cooks. Stir in the butter at the end for a hint and richness. Taste and adjust seasoning if needed.

Use immediately or let cool and store in the fridge for up to a week. Freezes like a dream.