Summer Green Beans in Aromatic Spiced Tomatoes

Ingredients

• 4 tablespoons butter
• 1 1/2 cups finely chopped onion (very)
• 1 tablespoon chopped garlic (finely)
• 1 tablespoon brown sugar (packed)
• 2 teaspoons kosher salt
• 2 teaspoons Garam Masala
• 2 teaspoons ground ginger
• 1/2 teaspoon ground coriander
• 1/2 teaspoon ground cinnamon
• 1/2 teaspoon brown mustard seeds (or whole yellow)
• 2 cups fresh tomatoes (peeled, seeded, and finely chopped, see Recipe Notes)
• 1/2 cup vegetable stock
• 1 1/2 pounds yellow wax beans (whole green and/or, ends trimmed and any tough strings removed)
• 1/2 teaspoon grains of paradise (ground, see Recipe Notes)
• 1 lemon