• 4 red and/or yellow bell peppers
  • 5 Tbsp. extra-virgin olive oil, divided

 

Prepare the vegetables
Cut 4 bell peppers and 1 poblano chile in half lengthwise. Using your fingers, pull out stems and ribs, then tap out seeds. Slice lengthwise into ¼” strips. Peel 3 onions and cut in half through root end. Cut a V-shaped notch into root to remove. Slice each half into 3 lengthwise wedges. Peel 6 garlic cloves and thinly slice.

 

Make the Sauce
Heat 2 tablespoons oil in a large Dutch oven over medium. Add onions and garlic and cook, stirring often, just until onions are beginning to soften, 5–8 minutes.

Add bell peppers, chile, and another 1 tablespoon oil to pot; season generously with salt and pepper. Stir to combine, then increase heat to medium-high. Cover and cook, uncovering to stir occasionally, until peppers are tender, 10–15 minutes.

Create a clearing in the middle of the pot and add 2 tablespoons tomato paste. Stir paste until darkened in color and is sticking to bottom of pot, about 3 minutes.

Add ⅓ cup vinegar and stir to dissolve paste and combine with peppers and onions. Cover and cook, stirring occasionally, until peppers and onions are very tender, 8–10 minutes longer. Season with more salt and pepper.

 

Saute the sausages
Slice sausages in half, lengthwise, to form long strips. Add 1 tablespoon oil to a large frying pan and heat until shimmering. Add sausages and cook, stirring occasionally, until both sides are golden. Remove from heat.

 

Assemble sandwiches

Slice 3 rolls lengthwise without cutting all the way through (so 2 sides remain attached).

Divide half of peppers and onions mixture among rolls, then arrange seared sausage halves over.

Top with remaining peppers and onion mixture. Cut sandwiches in half crosswise and serve.