Caramelized Onion Grilled Cheese Sandwiches with Summer Squash & Celery Salsa

Caramelized Onion Grilled Cheese Sandwiches

with Summer Squash & Celery Salsa

40 MIN
2 Servings
Wellness at Blue Apron
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Vegetarian
These recipes don’t contain meat, poultry, fish, or seafood.* They’re made with fruits and vegetables, grains, legumes, nuts, and seeds. *Select artisanal cheeses may contain animal-derived rennet.
Carb Conscious
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600 Calories Or Less
Coming in at 600 calories or less per serving, these recipes are ideal for those choosing to monitor their caloric intake without sacrificing flavor. The US Food & Drug Administration uses 2000 calorie daily intake for general advice. The 600 calorie cap equates to 30% of the total 2000 calories per day based on 3 meals per day with 200 calories remaining for snack or beverage.
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From the Test Kitchen

Caramelizing onion, or cooking it slowly to draw out its moisture, both softens it and transforms its flavor. We’re layering these gourmet grilled cheese sandwiches with melty fontina and caramelized Vidalia onion—a seasonal variety from Georgia whose exceptional sweetness is balanced here by a splash of tangy verjus. A bright celery and caper salsa gives a bit of contrasting crunch to our side of roasted summer squash. (Chefs, yours may be yellow squash, green zucchini, or grey zucchini).

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  • Nutrition
    PER SERVING
  • Calories
    630 Cals (est.)
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fresh
ingredients
time-saving
tips & techniques
Prepare the ingredients:
1 Prepare the ingredients:

Preheat the oven to 450°F. Wash and dry the fresh produce. Quarter the squash lengthwise; halve on an angle. Peel and thinly slice the onion. Small dice the celery; place in a medium bowl. Finely chop the parsley leaves and stems. Roughly chop the capers. Peel and roughly chop the garlic; using the flat side of your knife, smash until it resembles a paste (or use a zester). Thinly slice the cheese (discarding any rind).

Roast the squash:
2 Roast the squash:

Place the squash on a sheet pan. Drizzle with olive oil and season with salt and pepper; toss to thoroughly coat. Arrange in a single, even layer, cut side down. Roast 13 to 15 minutes, or until lightly browned and tender when pierced with a fork. Remove from the oven.

Caramelize the onion:
3 Caramelize the onion:

While the squash roast, in a medium pan (nonstick, if you have one), heat 1 tablespoon of olive oil on medium-high until hot. Add the onion; season with salt and pepper. Cook, stirring occasionally, 7 to 9 minutes, or until lightly browned and softened. Add the verjus and cook, stirring frequently, 1 to 2 minutes, or until the liquid has cooked off and the onion is thoroughly coated. Remove from heat; season with salt and pepper to taste.

Make the salsa:
4 Make the salsa:

While the onion cooks, to the bowl of celery, add the parsley, capers, vinegar, and as much of the garlic paste as you'd like; season with salt and pepper to taste.

 Assemble the sandwiches:
5 Assemble the sandwiches:

While the squash continues to roast, place the bread slices on a clean, dry work surface. Divide the caramelized onion and cheese between 2 of the bread slices; season with salt and pepper. Complete the sandwiches with the remaining bread slices. Wipe out the pan used to cook the onion.

Cook the sandwiches & plate your dish:
6 Cook the sandwiches & plate your dish:

In the same pan, heat 1 tablespoon of olive oil on medium until hot. Add the sandwiches. Cook, occasionally pressing down on the sandwiches with a spatula, 2 to 4 minutes per side, or until the bread is golden brown and the cheese has melted. (If the pan seems dry, add 1 teaspoon of olive oil before flipping the sandwiches.) Transfer to a cutting board; immediately season with salt. Cut the cooked sandwiches in half on an angle. Divide the sandwiches and roasted squash between 2 dishes. Top the squash with the celery salsa. Enjoy!

Tips from Home Chefs

1 Prepare the ingredients:

Preheat the oven to 450°F. Wash and dry the fresh produce. Quarter the squash lengthwise; halve on an angle. Peel and thinly slice the onion. Small dice the celery; place in a medium bowl. Finely chop the parsley leaves and stems. Roughly chop the capers. Peel and roughly chop the garlic; using the flat side of your knife, smash until it resembles a paste (or use a zester). Thinly slice the cheese (discarding any rind).

2 Roast the squash:

Place the squash on a sheet pan. Drizzle with olive oil and season with salt and pepper; toss to thoroughly coat. Arrange in a single, even layer, cut side down. Roast 13 to 15 minutes, or until lightly browned and tender when pierced with a fork. Remove from the oven.

Roast the squash:
Caramelize the onion:
3 Caramelize the onion:

While the squash roast, in a medium pan (nonstick, if you have one), heat 1 tablespoon of olive oil on medium-high until hot. Add the onion; season with salt and pepper. Cook, stirring occasionally, 7 to 9 minutes, or until lightly browned and softened. Add the verjus and cook, stirring frequently, 1 to 2 minutes, or until the liquid has cooked off and the onion is thoroughly coated. Remove from heat; season with salt and pepper to taste.

4 Make the salsa:

While the onion cooks, to the bowl of celery, add the parsley, capers, vinegar, and as much of the garlic paste as you'd like; season with salt and pepper to taste.

Make the salsa:
 Assemble the sandwiches:
5 Assemble the sandwiches:

While the squash continues to roast, place the bread slices on a clean, dry work surface. Divide the caramelized onion and cheese between 2 of the bread slices; season with salt and pepper. Complete the sandwiches with the remaining bread slices. Wipe out the pan used to cook the onion.

6 Cook the sandwiches & plate your dish:

In the same pan, heat 1 tablespoon of olive oil on medium until hot. Add the sandwiches. Cook, occasionally pressing down on the sandwiches with a spatula, 2 to 4 minutes per side, or until the bread is golden brown and the cheese has melted. (If the pan seems dry, add 1 teaspoon of olive oil before flipping the sandwiches.) Transfer to a cutting board; immediately season with salt. Cut the cooked sandwiches in half on an angle. Divide the sandwiches and roasted squash between 2 dishes. Top the squash with the celery salsa. Enjoy!

Cook the sandwiches & plate your dish:
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