One-Pot Pasta with Spinach and Tomato

By Lauren Mitchell, Test Kitchen Director · Reviewed by AislePrompt Editorial · Published 2026-05-03 · Updated 2026-05-03

A simple, nourishing one-pot pasta dish with fresh spinach and diced tomatoes. This italian-inspired one pot (vegetarian) ready in about 25 minutes pairs penne pasta, olive oil, yellow onion for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 350 calories and feeds 4, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Ingredients

• 8 oz penne pasta
• 1 tbsp olive oil
• 1 small, diced yellow onion
• 2 cloves minced garlic cloves
• 14 oz can diced tomatoes
• 3 cups vegetable broth
• 4 cups packed fresh spinach
• 1 tsp salt
• 1/2 tsp black pepper
• 1/4 tsp optional red pepper flakes
• 1/4 cup grated Parmesan cheese

Instructions

1. Step 1: In a large pot, heat 1 tbsp olive oil over medium heat. Add 1 small diced yellow onion and sauté for 3-4 minutes until translucent and fragrant.
2. Step 2: Add 2 minced garlic cloves and cook for 30 seconds until aromatic without browning.
3. Step 3: Add 8 oz penne pasta, 14 oz canned diced tomatoes with juices, 3 cups vegetable broth, 1 tsp salt, 1/2 tsp black pepper, and 1/4 tsp red pepper flakes (if using). Stir to combine.
4. Step 4: Bring to a boil, then reduce heat to medium-low and simmer uncovered for 12 minutes, stirring occasionally, until pasta is tender and most liquid is absorbed.
5. Step 5: Stir in 4 cups packed fresh spinach and cook for 2 minutes until wilted.
6. Step 6: Remove from heat and sprinkle 1/4 cup grated Parmesan cheese over the pasta, stirring gently until melted and combined. Serve warm.