Peel and devein shrimp if using unpeeled. Toss with olive oil, garlic, ginger and half of the salt and pepper amount in recipe. Refrigerate for a few hours if possible, otherwise refrigerate until all other ingredients are prepared.
Zest orange to get about 1 tsp of zest. Squeeze as much juice as possible, ideal amount would be about ⅓ cup. Add marmalade, soy sauce, rice vinegar and cornstarch, along with the rest of the salt and pepper. If using regular vinegar, use half as much as the acidity level is higher. Stir and set aside.
Prep vegetables for stir fry. Some snow peas have "strings" that can be easily peeled from edge. If using frozen broccoli florets, rinse and drain to defrost. Feel free to use any variety of vegetables, aiming for about 4-5 cups in total.
Pre cook noodles if using a type that requires cooking. Slightly undercook and rinse with cold water.
Meanwhile, heat large skillet to medium and add shrimp, including marinade ingredients all at once. Spread out so they are not overlapping and leave undisturbed for 60-90 seconds, depending on the size. Quickly turn shrimp and cook another minute or so on other side. Remove from pan to clean plate.
Add sesame oil to same pan and increase heat to medium-high. Add prepared vegetables (except zoodles if using) all at once and stir fry for 3-4 minutes. When vegetables are softening but still tender crisp, add shrimp back to pan, along with zoodles, noodles and sauce. Cook, stirring until shrimp is heated through, ingredients are well coated and sauce has thickened slightly.
Serve hot and garnish with green onions and sesame seeds if desired.